(1) Bacillary White Diarrhoea 52 (2) P.P.L.O. Scheme 52 (3) Pig Recording and Health Scheme 53
8. MEAT INSPECTION 53 9. STOCK INSPECTION SERVICES 53 10. ANIMAL HEALTH EXTENSION SERVICE 53 11. IMPORT AND EXPORT CONTROL 54
(1) Import 54 (2) Export 55
12. TRAINING 56 13. STOCK CENSUS 59 14. PUBLICATIONS 60 15. LEGISLATION 66 16. TECHNICAL RELATIONS WITH OTHER COUNTRIES 67
ANNUAL REPORT 1968/69
VETERINARY SERVICES
1. INTRODUCTION
Until recently the Veterinary Research Institute and the Division of Veterinary Services functioned to a large extent as separate organisations. They are now closely integrated under a Chief Director, although each retains its original respon-sibility. This new arrangement will facilitate efforts to solve the problems of the stock industry of the country. State Veterinarians in the various areas are being provided, as far as possible, with improved facilities to enable them to identify the local problems, and to attempt to find the solution to these. At five different centres namely Onderstepoort, Allerton, Stellenbosch, Grootfontein and Windhoek diagnostic laboratories have been created with more advanced facilities and apparatus to assist State Veterinarians with serological, chemical and general analyses of tissues and secretions of animals involved in these problems. In this way problems are being identified and brought to a satisfactory solution. Where further research is necessary to finalize the matter, it is referred to the Institute with its teams of researchers and advanced equipment.
Under the new system opportunities are offered to State Veterinarians who have investigated local problems to a state where research is necessary, to go to the Institute as a member of the team to which the problem has been assigned. If a solution is found the information is transmitted to the officers in charge of the area concerned and to the veterinary profession in general. In this integrated manner we hope to be of considerable value to the stock industry.
Another major re-organisational step involved an arrangement whereby a closer liaison was established between Veterinary Services in South West Africa and the Division of Veterinary Services in the Republic. This came into effect on April 1, 1969.
Sheep Scab was found in localised outbreaks in the Pietersburg district and the Witwatersrand area of Transvaal and also near the Transvaal-Cape Province border in the vicinity of Botswana.
During the second half of 1968 a serious outbreak of the mesogenic form of Newcastle Disease occurred in the Transvaal districts of Pretoria, Brits and Warmbaths.
Foot and Mouth Disease was diagnosed in cattle on three farms in the Barberton district during July 1968. As a result of the immediate application of stringent control measures, the outbreak was contained, and no additional farms became involved.
The first phases of schemes for the eventual total eradication of Bovine Tuberculosis and Brucellosis in both cattle and small stock were put into operation during the early months of 1969.
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During the year mucosal disease in bovines, which occurs in various parts of the world and is of economic importance especially in the U.S.A., was determined for the first time in the Republic on a farm in the Lydenburg district. Preliminary results of a serological survey reveal that the disease is possibly wide spread in the Republic, causing symptoms and mortality in only a small percentage of animals, subjected to stress. The serological survey will have to be completed before the development of a vaccine can be considered. One of the most important events in the past year was the occupation of the new building complex at Onderstepoort, which was officially opened by the Hon. the Minister of Agriculture on November the 8th, 1968. Apart from ample facilities for the production and handling of bacterial and virus vaccines, laboratories for bacteria-logical research and administrative offices have been provided. These facilities have placed the production and handling of vaccines on a more sophisticated and scientific basis and increased the production potential to a considerable extent. Extensive mechanisation has been introduced, with consequent saving in labour and material. After initial problems were encountered, bacterial vaccines such as enterotoxaemia are now cultured in fermentation tanks and fed to the final containers through pipe lines, where automatic bottling is carried out. A separate testing unit has also been established to determine the safety and efficacy of all vaccines in the production and final container stages, conforming to interna-nional standards. Arising from the development of an efficient oil adjuvant at this Institute, experiments have been carried out on the toxoid of enterotoxaemia with a view to involving a vaccine conferring a better and more prolonged immunity. It has been shown that the enterotoxaemia adjuvant vaccine gives a higher degree of immunity, which should last for more than a year after a single inoculation. This improved vaccine will be marketed within the near future. The experimental work on vaccines against vibriosis and three-day-stiffsick-ness (ephemeral fever) is nearing completion and these vaccines should be in production and available shortly. As a result of problems with production only a small quantity of live vaccine against colibacillosis and colisepticaemia of calves and lambs was prepared and issued. Research has however shown that a dead vaccine confers a better protection than live attenuated bacteria. Further experiments are progressing to develop a dead vaccine for the purpose. At the request of the Division of Veterinary Services, S.W.A. region, a vaccine against lungsickness (pleuro -pheumonia) has been prepared at Onderstepoort, using the KH3J strain, with a view to future requirements in combating the disease in cattle in Ovamboland. This vaccine was tested in a controlled experiment in Ovamboland and compared with a similar from Angola. From this it appears that the Onderstepoort vaccine is safe and acceptable, conferring satisfactory protection against artificial exposure to infection.
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2. NOTIFIABLE DISEASES (1) Foot and Mouth Disease
In the Komati Ward of the Barberton district Foot and Mouth Disease was diagnosed on one farm on July 17, 1968 and within one week on two adjacent farms. The outbreak was subsequently proved to be due to S.A.T. 1. Control measures on the infected properties included the artificial virusing of the 168 cattle involved, confining animals to kraals where they were fed and watered, the placing of a cordon round the three farms, the creation of a stock-free zone around the farms, the setting up of road blocks on the road through the farms to ensure that no transportation of any animal or other material capable of transmitting infection took place. At the same time intensification of short-interval inspections and other restrictive measures were introduced in the rest of the Komati Ward. As the outbreak was contiguous to the Kruger National Park, thorough inspec-tions were carried out in the adjacent Park area. A total of 113 animals were caught and examined, and 1 970 examined post mortem, but no elinical cases were found. Serum samples and oesophageal/pharyngeal scrapings taken from animals in the Park, however proved positive for S.A.T. 1, 2 & 3. Throughout the year vigilance was maintained against the introduction of disease by animals straying or illegally moved from adjacent territories. This necessi-tated the destruction of 38 cattle, 16 sheep and 68 goats , with a total value of R2 705. Further precautionary measures against the introduction of Foot and Mouth Disease include short interval inspections of all susceptible stock in the border and other danger areas as well as regular patrol and repair of fences on the international borders and along the Kruger National Park. Patrolling the western and southern Park fences alone required, 66 628 vehicular miles, while 11 415 breaks in the fence, involving 75 130 single strands and 60,954 bent standards, had to be repaired. (2) Rabies During the report year a total of 735 specimens was examined by the Veterinary Diagnostic Centre at Onderstepoort. Of these 260 (36,7%) proved posi-tive for rabies. This represents a slight increase in both total specimens submitted and positive cases. Positive findings were recorded in the following species:
Meercats 81 Meerkatte Catlle 81 Plaasdiere Dogs 40 Honde Wild cats 17 Ander wilde diere Genets 15 Ander wilde diere
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Cats 13 Katte
Jackals 4 Jakkals Sheep 3 Plaasdiere Other animals 6 Ander wilde diere
Compared to the previous 12 month period, a distinct improvement in the epi-zootic canine rabies areas of Natal and Transvaal is reflected in the reduced incidence of the disease in domestic canines. This reduction is however more than offset by the marked increase in viverrid and bovine rabies. Particularly noticeable is the big rise in the number of cases involving the genets, the majority of which occur in the Kuruman, Vryburg and Postmasburg districts. Another significant rise is seen in the wild felidae, and these together with the genets give rise to concern as the majority are associated with attacks on human beings. From the available data it may be concluded that the annual immunisation of dogs in the declared rabies areas of the Natal and Eastern Transvaal Regions is yielding dividends. Otherwise the trend appears to be still upwards, though whether this is absolute or merely relative is impossible to assess. From the O.F.S. Region a sharp increase from 65 confirmed cases during 1967/68 to 92 during the current year is reported, while the Natal Region recorded a dramatic improvement. The operation of the mobile units in recognised infected areas continued during the year. These units destroyed populations of jackals and viverridae, and carried out field investigational work. On 124 457 morgen (147 farms) on the Central Plateau, eradication of viverridae was undertaken, and 47,422 colonies and 41,871 single holes gassed. The policy of immunising all dogs within a radius of 10-15 miles around all confirmed outbreaks was continued during the year. A total of 161 033 dogs and 3 861 cats were immunised, in routine annual vaccination in the declared rabies areas and in the vicinity of outbreaks. It is of interest to note that analysis of the positive results obtained in the laboratory of the Diagnostic Centre at Onderstepoort reveals that of the 260 cases, 252 were diagnosed by the application of the F.A. test, and the remaining 8 were diagnosed histologically as no specimen in 50% glycerol was submitted. In no case was a positive specimen missed by the F.A. test. Also F.A. conjugate produced in this laboratory is in use in Botswana, Mocambique, Rhodesia and Malawi, while suspect rabies material from S.W.A. and Swaziland is examined here.
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(3) Antrax During the year 19 outbreaks occurred – an increase of 6 on the precious year. These resulted in the mortality of 16 cattle, 18 sheep, 1 horse and an unkown number of game animals. The latter succumbed in an outbreak in the north eastern corner of the Kruger National Park. In 3 outbreaks in non-white locations in the Eastern Cape an unkown number of Bantu and Coloureds died as a result of ingesting or handling the meat of infected carcasses. A total of 4 582 924 cattle, 75 023 small stock, 1 324 equines and 63 pigs were vaccinated by or under supervision of officers of the Division. In view of the fact that so many officers of the Division were absent from normal areas on campaign duties, the figures for precautionary inoculations are gratifyingly high. This was most likely due, in part at least, to the fact that vaccine for compulsory annual inoculation is now a free issue, thus dispensing with the irritating and time consuming delays by the non-availability of vaccine when officers arrive on farms for the official annual vaccinations. (4) East Coast Fever and Related Diseases Since 1954 no outbreaks of East Coast Fever have occurred in South Africa, but in the previously infected potential danger areas vigilance is still maintained. The highest possible percentage of spleen smears from cattle that die or are slaughtered is collected and examined. Out of a total cattle population of 3 066 354 in these areas, 350 679 deaths occurred and 334,647 spleen smears were collected for examination, resulting in the diagnosis of 4 cases of Buffalo Disease (Theileria lawrencei) and 45 cases of Benign Bovine Gonderiosis (Timutans) The latter two diseases were controlled by quarantine and intensified tick control measures. (5) Tuberculosis Until recently the combating of bovine tuberculosis depended on the voluntary participation of cattle owners in either the interim or accreditation schemes. All tests for the latter scheme were carried out by State Veterinarians as a free service, while testing under the interim scheme was performed chiefly by private veterinary practitioners at owners’ expense. Disposal of reactors was the responsibility of owners. The State gave no compensation or any other financial aid. During the report year the first steps towards an extension of the campaign aimed at eventual total elimination of the disease, were taken. In the first instance more extensive use was made of the services of private practitioners, who carried out tuberculin testing under both the interim and accreditation schemes at State
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expense. Secondly, all tuberculosis infections found at tuberculin testing, abattoir slaughter, milk examination or by any other means , were traced back to the herd of origin, if possible. This herd was then placed under official control, with compulsory testing, and elimination of reactors with compensation by the State. Testing for diagnostic or export purposes was carried on as in previous years. The tests performed are tabulated below:
TEST NUMBER OF HERDS
ANIMALS TESTED
RESULTS
POSITIVE SUSPICIOUS I.N.H.
12 4 848 351 21
IMPORT AND EXPORT
321 6 039 13 6
DIAGNOSTIC
649 33 501 314 394
INTERIM 741 67 249 583 494
ACCREDITATION
426 53 461 11 113
2 149 165 098 1 272 1 028
The total number of animals tested shows an increase of 19,526 compared to 1967/68 and represents 1,57% of the total cattle population of the Republic. The incidence of reactors – tests under the accreditation scheme excluded – is 1,13% positive and 0,82% suspicious. Three outbreaks of tuberculosis in poultry were recorded during the year; one each in small chicken flocks in the O.F.S and Winter Rainfall Regions, and the third in a group of 29 turkeys in the Highveld Region. In all three cases eradication was accomplished by slaughter of the whole flock.
Condemnation of pig carcasses at abattoirs for either generalised or localised tuberculosis continue to inflict heavy financial loses. In this connection the Veterinary Research Institute, Onderstepoort reports that previous studies indicated that the recent increase of tuberculous lesions in pigs was due to mycobacteria other than the classical tubercle bacilli. In a survey of 340 tuberculous lesions in porcine lymphnodes collected at the abattoirs of Estcourt, Heidelberg (Tvl), Vereniging and Durban, avian-like (para-avian) mycobacteria were isolated from 161 lesions (47%) and human tubercle bacillilus from 18 (5.3%) while the bovine tubercle bacillus was found in only 1 case. The lesions caused by the avian-like mycobacteria were indistinguishable from those caused by classical tubercle bacilli.
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Samples of pig meal and dust and bedding were collected in piggeries where the pigs frequently showed tuberculoid lesions, and 70% of feed samples and 80% of environmental (bedding and dust) samples yielded non-chromogenic mycobacteria, the majority of which resembled but were not identical to the avian tubercle bacillus.
It is concluded that avian-like mycobacteria occurring freely in nature are responsible for 95% of tuberculous lesions in the lymphnodes of pigs. Condemnation of the carcasses of these pigs is not justified, but macro- or microscophical examination is not able to distinguish cases of true TB from TB-like lesions.
The Research Institute also reports that those organisms which interfere with the diagnosis of tuberculosis in cattle, pigs and man, are undergoing an extensive taxonomic study. We are working in collaboration with the International Union Against Tuberculosis, the American Type Culture Collection, and the International Working Group on Mycobacteria Taxonomy. The Tuberculosis Section is also the reference laboratory for South Africa, and was instrumental in the compilation of a Laboratory Manuel which will be published by the Department of Health.
A system was established whereby an anonymous mycobacterial strain can be typed as one of the 25 known species of mycobacteria. It consists of six cultural tests, nine biochemical tests, pathogenicity studies in five species of laboratory animals, one serological test and eight allergenic skin tests. It was proved that several new species of mycobacteria described overseas also occur in S.A., and that they can infect man as well as animals. The Onderstepoort Institute produced 286,110 units of bovine tuberculin and 127,630 units of avian tuberculin during the year. This represents and increase of 47,3% and 123,3% respectively. Research workers report that as the Institute is now producing tuberculin for use in humans as well as in cattle, its purification, standardization and stability is under renewed scrutiny. Antigenic relationships between pathogenic tubercle bacilli and mycobacteria occurring freely in nature give rise to many low grade non-specific tuberculin reactions in man and cattle. The specificity of our three PPD tuberculins was examined in 980 tests on 216 artifically sensitized guinea pigs. Specificity differences were larger between avian and human PPD. Human TB strains sensitize guinea pigs more strongly to avian PPD than bovine TB strains. Most mycobacteria occurring in nature sensitize guinea pigs to avain PPD. To obtain purer, highly specific PPD’s the absorption of non-specific antigenic fractions to living cells in vitro is studied. After nine experiments involving 2,300 skin tests on guinea pigs it could be shown that unwanted fractions of PPD can be neutralised by sensitized spleen cells and the “purified” antigen then used for
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diagnosis. The highest increase in specificity difference was achieved when avain PPD was exposed to guinea pig mononuclear cells which had been sensitized to bovine tuberculo-antigen. In connection with new anti-tuberculosis drugs, research workers at Onderstepoort state that the effect of Ethambutol was assessed in 47 patients with chronic lung tuberculosis. They were Bantu with an average age of 41 years, who had been treated previously for an average period of 49 months, their treatment having failed due to resistance to the major anti-TB trugs. Clinically, many were in poor condition, and their X-rays showed advanced lung TB or extensive destruction. The drug was used at 25 mg/kg per day for 2-3 months, and thereafter at 15 mg/kg per day. The organisms had been grown on culture previous to the trial, and their drug sensitivity pattern established. Half rest received 1-2 additional effective drugs. Except for one case of temporary blurred vision, no side-effects occurred with the drug, Clinically, all but three patients improved, and the average weight gain was 12 lbs. After each 3-month period a quarter of the cases were lost to the study due to various reasons. The bacteriological results were taken as the only valid oriterion for the evaluation of such chronic cases, and they showed a conversion from positive to negative sputum in two-thirds of the patients after three months treatment. The first three relapses occurred after 6 months and another two after 9 months. There was no change i.e. failure of treatment in four cases. Ethambutol is a very valuable drug in the treatment of multiresistant chronic pulmonary tuberculosis, but it should always be given in connection with other drugs, and it is too expensive for use in animals. Scientists at Onderstepoort report that in a study of the characteristics of tubercle bacilli causing pulmonary tubercolisis in the Bantu, a five year survey of 17 000 non-whites (96% being Bantu) in all regions, except the Western and Northern Cape, has been concluded. Tubercle bacilli were isolated form 9 940 persons. Only one strain was of bovine origin and one of the avain type, all the others were typical human tubercle bacilli. Four patients suffered from mycobacterioses of the lungs caused by a typical mycobacteria. It is concluded that in South Africa animals are not a source of tuberculosis in humans. The tubercle bacilli of 5 440 patients with newly diagnosed lung tuberculosis were tested for their sensitivity to the four major anti-tuberculosis drugs. It was found that before treatment sterts, 10% of strains are resistant to Isoniazid and 5% resistant to Streptomycin. For PAS and Thiacetazone the incidence of primary resistance is negligible (2%).
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The TB-organisms of 4 500 hospitalised patients were insolated during their
intensive therapy period and these were tested for sensitivity against seven anti-TB drugs. The first drugs to which the bacilli become resistant are usually Isoniazid and Streptomycin. Two-thirds of Patients who had not been cured after 6 months of treatment excreted resistant tubercle bacilli. Drug resistance is the major cause of treatment failures. (6) Brucellosis The voluntary vaccination especially of heifer calves, with Strain 19 vaccine in the campaign against contagious abortion in cattle, met with a large measure of success over the past years. The stage had now been reached where, as a first step towards the final eradication of the disease, the vaccination of all heifers between the ages of 3 and 10 months was made compulsary by a proclamation issued on December 13, 1968. Where such immunisation is done under official supervision, the heifers receive a distinctive earmark to facilitate ready identification when the final stage of elimination of infected animals is reached. At the same time an embargo placed on the vaccination of breeding stock over the age of 10 months, unless warranted by circumstances, and then only on the written authorisation of a State Veterinarian. In the case of Brucella ovis infection is sheep, propagation of voluntary vaccination of ram lambs with Rev. I vaccine was continued. In terms of the proclamation referred to above, any flocks of small stock in which either B.abortus or B.melitensis infection is established, are placed under official supervision with compulsary vaccination, until the disease has been eliminated from the flock. Serological tests for brucellosis carried out during the year are reflected in the table below:
SPECIES NUMBER TESTED RESULT POSITIVE SUSPISIOUS
Cattle
Sheep
Goats
33 844
7 359
25
2 843 (8.4%)
289 (3,9%)
-
667
222
2
In the Kruger National Park 181 serological tests conducted on buffalo, elephants, baboons, guns, rhinoceri and humans and humans, revealed a title only in 8 of 97 buffalo examined. During the year Onderstepoort issued 943 912 doses of Strain 19 and 422,100 doses of Rev. I vaccine. A total of 317 herds with 24,273 cattle and 2 flocks with 14,484 sheep were vaccinated by officers of the Division.
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(7) Trypanosomiassis 1. Nagana No positive cases of nagana were diagnosed in the Republic of South Africa, while two cases were diagnosed and successfully treated in the Easter Caprivi. Tsetse fly spraying operations were continued beyond the borders of the Republic in Rhodesia and in Mocambique as well as in the Caprivi tsetse fly complex. Another joint annual spraying operation was undertaken in the West Sabi-Lundi area, known as the south eastern tsetse fly front, which threatened the Kruger National Park as well as the adjoining areas in Rhodesia and Mocambique. In the light of the results of comparative field trials carried out by the Rhodesian Tsetse Research Section during 1967, which had shown that the highly dispersable 75% DDT wettable powder, when used as a suspension containing 5% active ingredients, is at least equally as effective and persistent against tsetse flies as the much more costly 3.1% dieldren emulsion used in all the earlier campaigns, it was agreed that a complete change-over from Dieldren to the cheaper DDT should be made for the 1968 operations.
In addition it was decided that top priority must be given in a combined effort to open up as quickly as possible an extensive system of new access roads in the hitherto almost trackless and heavily bushed region extending eastwards into Mo-cambique. Rhodesia was responsible for the planning and pegging of the new access lines whilst Mocambique supplied two Cartipillar D6B bulldozers and opera-tors to open up the tracks and South Africa supplied fuel and oil for 220 miles of access roads completed in Mocambique.
During the 1968 spraying operations in Rhodesia 5 spraying teams, each with 4 hand operated pneumatic sprayers, covered a total of 605 miles of riverine, valleys, pans contacts and grid spraying over an area of 175 square miles. A total of 5 tons and 1.900 lbs of DDT 75% wettable powder was used in 17,800 gallons of 5% DDT suspension.
In Mocambique 7 spraying teams covered a total of 2,319 miles of reverine, valleys, pans, contacts and grid spraying over an area of 917 square miles. A total of 15 tons and 1,850 lbs of DDT 75% wettable powder was used in 51,260 gallons of a 5% DDT suspension. In the flat bushed country in Mocambique, with vast areas of ill-defined tsetse habitat it was decided to resort to grid spraying as it was done in similar type of country in Rhodesia in 1967. The free movement of properly documented tsetse control personnel across the international border was previously arranged through the governments concerned.
It was provisionally estimated and planned that of the joint spraying operations which started the beginning of July 1968 and was completed on the 20 th September 1968, approximately one third of the total effort would be expended in Rhodesia and two thirds in Mocambique. This was mainly because of the progress made with major efforts in Rhodesia the previous years.
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The contribution made by South Africa included one Senior Technical Officers,
4 Stock Inspectors, 6 3-ton lorries with drivers, 3 Land Rovers, 15 000 lbs 75% DDT wettable powder, fuel and oil for access roads and maintenance costs. The financial contributions from the respective territories towards the 1968 joints spraying opera-tions were as follows: Republic of South Africa Rhodesia Mocambique Total R22 246 R17 162 R18 716 R58 124
In Rhodesia spraying operations were confined to mopping up operations in a relatively confined area adjoining Mocambique, south of Lundi river. These were the remaining low residual tsetse fly foci as was determined by organised fly surveys during the year with bait cattle, test herds and cycle rounds. In Mocambique the spraying operations extended from the Rhodeia – Mocambique border, south of the Save river approximately 100 miles eastwards towards Massegena, to include all the remaining residual tsetse fly country in this area. The results obtained after the spraying operations were, as in the past, evaluated from planned surveys with bait cattle, cycle rounds, the incidence of trypanosomiasis in test herds and field observations. The indications are that certain residual fly foci were eliminated, while in other areas the fly desity was further reduced to such low levels that their presence, in certain confined areas, was only detected by intensive surveys with bait cattle. Further satisfactory progress was therefore made in all parts of the operations area and the overall tsetse control problem has thus been further reduced to the more difficult final stages of locating and eliminating the remaining low residual fly foci. For the second year surveys with bait cattle used in the vast are between the Sabi and Lundi rivers in Rhodesia, indicated that further spraying operations were not justified there, while south of the Lundi river, foci of low densities of tsetse flies were still located in a confined area adjoining Mocambique. In Mocambique more intensive and organised surveys had to be planned with bait cattle and cycle rounds, to define the remaining fly foci. This was possible with the additional 220 miles of access roads which were constructed and which will also greatly facilitate the final stages of spraying operations in Mocambique. Eastern Caprivi Zipfel As in the past the funds for the 1968 spraying operations in the Eastern and the Western Caprivi were provided by the Department of Bantu Administration and Development while the campaign was organised and controlled by the Division of Veterinary Services. These operations were however extended to include the whole of the Eastern and the Western Caprivi extending westwards to Bwabwata in Western Caprivi as well as the adjoining area in Angola which is situated halfway between the Kwando and the Okavango riviers. One spraying team operated from
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Bwabwato to include all the tsetse fly infested country in West Caprivi from 15 miles west to 20 miles east of Bwabwata to stop the advance of the fly which threatened the Okavango drainage area. In addition the M.C.T Organisation from Angola embarked on their co-ordinated spraying operations in the adjoining area to the north east of Bwabwata. In addition two spraying teams first completed the necessary mopping up operations in Eastern Caprivi, where tsetse fly advanced across the Kwando rivier from the unsprayed western banks of the Kwando river in two confined areas, before proceeding with spraying operations to the west of the Kwando river, to include all the known tsetse fly infected country in Western Caprivi and so link up with the Bwabwata spraying operations. The total costs of the spraying operations over an area of approximately 1200 squire miles amounted to R17 050 of which the Division of Veterinary Services contributed R5 612. A total of 2000 gallons of Dieldrex 15(T) was used in a 3.1% emulsion and 400 lbs. 75% DDT wettable powder in a 5% dispersion. This is the first year in which the control of the Caprivi tsetse fly complex, which also involves human sleeping sickness, was extended into the Western Caprivi and undertaken on an international basis with Angola, to stop the westward advance towards the Okavango river. The results of the follow-up surveys in the Eastern and in the Western Caprivi, after the 1968 spraying operations are most encouraging. The indications are that the 1968 campaign, in conjunction with the planned spraying operations for 1969 on an international basis with Angola, will not only stop the advance of the tsetse fly towards the Okavango river, but will reclaim a considerable area and so also effectively divide the Caprivi Tsetse fly complex into two separate compartments, which could then be considered and dealt with as the northern tsetse fly problem in Angola, and the southern tsetse fly problem in Botswana. The Eastern Caprivi remains free of the tsetse fly, except for localised areas where dispersion occurs across the Kwando river from the as yet unsprayed western banks of this river in Botswana. Due to the heavy floods experienced during the past two years area still remains inaccessible. During the period 1958 to 1964, when chemotherapy was resorted to in the Eastern Caprivi the cattle population increased from just over 9,000 to over 15 000. At the commencement of spraying operations in 1964 prophylactic chemotherapy was discontinued in the Eastern Caprivi and by September 1967 the cattle population increased to 20 968 with a further increase to over 24 000 by July, 1968. The present position has now changed to that the Eastern Caprivi, administered by South Africa, and the Western Caprivi under S.W.A Administration, is no longer directly implicated in the tsetse fly complex involving the Kwando and the Okavango river drainage areas.
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2. Dourine As in previous years, serum specimens were examined for dourine in connection with suspected cases, mares intended for breeding to valuable sires, and all enquines intended for export. During the report year 906 specimens from all over the Republic were submitted to Onderstepoort for investigation. Of the 13 positive cases, 5 stallions were castrated, 3 mares and 1 stallion sent to Onderstepoort for experimental work and 4 animals destroyed. Details of the 411 specimence received from beyond the borders of the Republic are tabulated below.
COUNTRY OF ORIGIN TOTAL SPECIMENS NUMBER POSITIVE South West Africa 230 18 Lesotho 3 Swaziland 22 Botswana 37 17 Rhodesia 88 Zambia 31
(8) Lumpy Skin Disease Although lumpy skin disease was reported from all of the 7 regions of the Republic, very few outbreaks were recorded. As the disease ran a mild course in affected animals and only a very small percentage of animals in any herd showed symptoms, losses were minimal. Of 18 471 cattle on 81 farms, 290 were reported affected. A total of 34 306 animals on 127 farms were immunised by or under the supervision of the inspectorate staff of the Division. Onderstepoort issued 563 367 doses of vaccine during the year. This represents a decrease of 54,6% on the 1967/68 issue of 1 241 579 doses, which was sufficient to protect just over 10% of the total cattle population of the Republic. (9) Sheep Scab Intensive follow-up inspections in the area involved in the 1967/68 outbreaks, revealed infection in 20 sheep of a total of 429 on 2 farms in the Soutpansberg, and 1 806 of 4 171 on 14 farms in the Pietersburg district of Transvaal. To eradicate the infection, 3 726 sheep and 7 942 goats were dipped on infected properties, and 39 627 sheep an 18 485 goats on contact farms. One outbreak occurred in the Transvaal district of Krugersdorp, where all 11 sheep in a flock were infected. This flock, and the sheep on contact farms, were dipped.
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In the Potgietersrus district of this province 4 outbreaks occurred, involving 241 sheep. During the eradication campaign 9 112 sheep and 103 636 goats inspected. During February 1969 a recrudescence of scab was found on a farm which had been infected during the previous year in the Tulbagh district of the Cape Province. It is considered likely that infection was spread by a sheep which had sheltered on an island in the Berg River during the previous campaign, and had therefore missed the dipping. The outbreak was successfully terminated by the usual control measures. On May 1, 1969 scab was established on a small holding in the Kenhardt district of the Cape Province. Inspections revealed 3 additional foci on premises in the vicinity. To control the outbreak, a total of 4,141 sheep and 616 goats were dipped on the 4 small holdings as well as 7,060 sheep and 569 goats on contact farms. On one farm in each of the Mafeking (Cape) and Lichtenburg (Transvaal) districts an outbreak occurred involving 130 sheep infected in the first and 1 in the latter case. In the Mafeking outbreak a total of 56,813 sheep were dipped and 435 sheep in Lichtenburg. (10) Mange Sporadic cases of mange in cattle, goats, horses and pigs were recorded, as tabulated below. All these outbreaks readily respended to hand dressing or dipping of infected and, where necessary, contact animals.
SPECIES NUMBER OF OUTBREAKS ANIMALS INFECTED ANIMALS ON FARMS
In the Kruger National Park Sercoptes scabei has been implicated as the cause of mange in the gnu, impala and giraffe. So far all attempts at the transmission of Psoroptes bovis, the casual agent of mange in the buffalo, to cattle, have been unsuccessful. (11) Swine Fever Classical Swine Fever does not occur in the Republic. During the year no oases of African Swine Fever were recorded. A small portion of the Northern and Eastern Transvaal is regarded as an enzootic swine fever area because of the presence of warthogs and bush pigs, potential carriers of the disease. Strict control is maintained over all movements of
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pigs and pork products within and out of this declared area. The movement of pigs to outside this area is permitted only from approved piggeries which conform to strict specifications and are subject to regular inspection, and then only to specific quarantine abattoirs. Meat products from these abattoirs may not be exported. (12) Swine Erysipelas During the year 10 outbreaks were confirmed, 6 in the Eastern Cape, 2 in the Winter Rainfall Area and 2 in Natal. One of the latter was diagnosed at the abattoir to which pigs had been consigned from the O.F.S. Infection readily responded to antibiotic treatment in all cases where this was necessary. (13) Epizootic Lymphangitis No cases of this disease were recorded during the year under review. (14) Johne’s Disease The disease was confirmed on 2 farms in the Caledon district of the Winter Rainfall Region. In the Transvaal it was diagnosed in a Charolais cow imported 5 years ago. This animal was removed to Onderstepoort for further examination, while her calves have been isolated. In Natal an imported bull moved from the Pieter-maritzburg district to Hlabisa was destroyed in extremis and the disease confirmed. No further cases have been found on the Pietermaritzburg farms. (15) Infections Laryngotracheitis This disease was diagnosed in two small flocks and in a poultry plant in the Transvaal. In the latter case 19 000 adult birds were vaccinated in an attempt to control the disease. An apparently non-pathogenic form was established on a poultry farm in the Simonstown district of the Cape Province, where regular inspections are being carried out. (16) Rinderpest This disease does not occur in the Republic of South Africa or the neighboring territories. (17) Newcastle Disease As indicated in the previous annual report the last outbreak of the mesogenic form of Newcastle Disease in the Western Cape epizootic for the year 1967/68 was recorded at the beginning of April 1968. This fortunately proved to be the final outbreak in that Region.
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As a precautionary measure, vaccinations were continued up to October 11, 1968, whilst intensive short interval inspections of all poultry were carried out until February 1969. A further 6 607 103 vaccinations were carried out during the current year bringing the grand total for the whole campaign to 25 171 967. The number of poultry inspected decreased gradually from 19 million in July, 1968 to 14 million in February, 1969; the inspection staff was reduced from 97 to 20 during the corres-ponding period. On July 22, 1968 Newcastle Disease was diagnosed in a fowl on a property in a suburb of Pretoria. Three days later the disease was confirmed on a farm on the north western outskirts of the city. During September 1968 the disease was found to be widespread in the Bantu areas to the north west of Pretoria. The Pretoria City outbreak is believed to have originated from a parrot bought from a dealer on the Witwatersrand, amongst whose parrots Newcastle Disease was confirmed on August 5, 1968. There is a very strong suspicion that these parrots were illegally introduced into South Africa. The origin of the subsequent outbreaks remains obscure. Immediately the disease was confirmed, strict control measures were insti-tuted. These included destruction of all infected or incontact birds, disinfection of infected premises, inspection of all poultry in the surrounding areas, collection of all dead poultry for laboratory examination at Onderstepoort, vaccination of all poultry at risk, the institution of quarantine measures and permit control of the movement of all poultry and poultry products. In all, 74 foci of infection in the Pretoria, Brits and Warmbaths districts were established. The last outbreak occurred on November 13, 1968. The summarised data presented below gives some indication of the amount of work and extent of organisation involved: Total number of vaccinations …………………………… 1 170 181 Total number of birds inspected ………………………… 86 570 363 Total number of birds destroyed ………………………… 32 680 Total mileage covered …………………………………… 729 580 Number of officials engaged in campaign ……………… 227 During the year Newcastle Disease was also diagnosed in a small flock of fowls on a farm in the De Aar district. The flock was slaughtered, and no spread occurred. A parrot sent to Onderstepoort for examination for psittacosis, was reported positive for Newcastle Disease. A blood specimen from its cage mate proved negative. No further action was taken. As last year, the Institute played an important part in the rapid confirmation of diagnoses and preparation of vaccine as well as the dissemination of advice.
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The method of control by eradication rather than “peaceful co-existence” was seriously criticized by some individuals. The success attained with eradication must be attributed to strict field control, early diagnosis after the outbreak commenced and the use of an efficient vaccine. It was proved once agaian that the method of vaccination and the choice of vaccine had been successful.
This was the first occasion in the history of a modern poultry industry that the fatal form of Newcastle disease was successfully eradicated.
The collection of virus isolates made during the outbreak lends itself to a study
of the characteristics of the virus. It has already been established that the isolates can be divided into three groups according to their virulence. It has further loan found that the role played by pigeons and pet birds such as parrots in the appearance of the disease, should not be underestimated. Experimentally it has been found that the disease can be transmitted form fowls to pigeons and that the latter can again transmit the disease to poultry.
The outer covering of the virus has been successfully separated from the
infective nucleic acid, and this non-infective outer covering (called agglutinine) is a very specific protective antigen, which might be utilized as a dead vaccine. Fowls inoculated with this substance showed a promising immunity. The advantage of such a vaccine is that it is free of vaccine reactions. Further investigation into the practical use of this is being continued.
(18) Bacillary White Diarrhoea and Fowl Typhoid During the year 8 outbreaks of B.W.D. (2 in the flocks of certificate holders) and 30 of Fowl Typoid (one in the flock of a certificate holder) were recorded. Summarised below is data of tests performed in connection with these two diseases: Flocks tested 161 Birds tested 785 640 Positive reactors found 315 Suspisious reactors found 68 D.W.D & F.T. Free Certificate holders 193 Birds in flocks or Certificate holders 3 447 012 The research Institute, Onderstepoort issued 1 643 400 doses of Fowl Typhoïd vaccine during the year. (19) Fowl Cholera No outbreaks of this disease were reported during the year.
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(20) Psittacosis Only 2 outbreaks were recorded, one in pigeons in the Parys, and one in parrots in the Pretoria district. Control of infection was successfully established by appropriate treatment. (21) Other Notifiable Disease 1. Scrapie Outbreaks of this disease were diagnosed in two flocks in the Barkly East District of the Eastern Cape Region. One flock was slaughtered, and arrangements are in progress for slaughtering the other. All flocks to which movements of potentially infected sheep have been traced, are regularly inspected, and all movements from these flocks are subject to permit control. 2. Equine Infection Anaemia Suspected cases of the disease, reported by a private practitioner in the Pretoria district, could not be confirmed by the Research Institute, Onderstepoort. An outbreak of a disease which claimed the lives of 4 horses in the Victoria West district, could also not be confirmed as Equine Infectious Anaemia . 3. Glanders and Bovine Pleuropneumonia (Lungsickness) For many no cases of these two diseases have occurred in the Republic of South Africa. 3. NON-NOTIFIABLE DISEASES (1) Deficiency and Nutritional Diseases
Over the greater part of the country, but especially in the Eastern Cape, Highveld, O.F.S. and Transvaal Regions the supplementary feeding of stock necessitated by drought very often caused metabolic disturbances. The injudicious use of mineral and trace element mixtures recommended by feed firm representative often aggravated the position by causing imbalances of these elements.
In the O.F.S. it has been known for some time that a magnesium deficiency often develops when sheep utilise green artificial pastures at certain times of the year. During the autumn of 1969 this condition occurred very widespread over the central and southern O.F.S and varied from acute cases with mortalities to sub-acute cases in both sheep and cattle. The administration of magnesium, either intravenously or in licks, gave satisfactory results.
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Very many instances of the abnormal deposition of calcium in arteries, veins,
and kidneys and on the surfaces of viscera, in both sheep and cattle were again encountered in the O.F.S Region. This condition is induced when magnesium is deficient and calcium abundant. In the Transvaal bushveld areas owners made increasing use if licks and blocks to combat aphosphorosis. The Natal Region reports that intensification of farming practices and the increasing use of heavily fertilised artificial pastures is leading to an increase in metabolic and nutritional disorders, and mineral deficiencies and imbalances are being encountered on an increasing scale. Diseases of metabolism are regarded as of major importance in the Winter Rainfall Region, and the problems are being attached with all available facilities. The Onderstepoort Research Institute reports that in a long term experiment of three years duration with sheep on a solitary diet of green oat feed cut from established pastures, no clinical cases of hypomagnesaemia or grass tetany could be produced.
The supplementation of green oats with potassium salts in excess of requirements, did not produce low magnesium values of the blood. There was a tendency for a depression of both calcium and magnesium values of the blood, but was inherent in the green oats without supplementation.
Excessive fertilization of green oats with potassium was not a factor in causing
low magnesium values of the blood, under our conditions. The possibility of other factors, such as high ammonia in the green feed,
inclement weather conditions, and low fibre intake need consideration in further studies.
The Institute further records that the need for phosphatic supplements in the
feeding of stock had resulted in further experimentaction on two batches of mono-ammonium phosphate on their feeding value for ruminants. The utilization of phosphorus and nitrogen were studied, and in a third group compared with N utilization of urea.
The 1967 batch of mono-ammonium phosphate had comparatively higher
retention values than a 1968 batch. Nitrogen retention in the urea group was only slightly better than in the mono-ammonium group.
From the results obtained it is obvious that the fertilizer brand of mono-
ammonium phosphate tested here had low phosphorus and nitrogen feeding value, but compared favorably with urea N utilization.
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Average Retentions: Digested
P N Ca Dry matter N
Batch 1967 Control Group 16.3 34.4 18.4 71.8 66.2
Mono Amm. Group 25.1 37.8 18.7 69.5 72.0
Urea Group 23.4 40.8 19.9 69.5 75.0
Batch 1968 Control Group 20.2 26.9 21.6 71.4 70.8
Mono Amm. Group 15.8 24.2 15.2 68.4 69.2
Urea Group 25.3 28.1 22.6 70.5 71.9
At Onderstepoort the research activities of the Department of Physiology are
mainly concerned with the causes of “Geeldikkop” and Enzootic Icterus in sheep and goats. Good progress has been made in the past twelve monts. It has, amongst others been proved that:
a) both syndromes are different manifestations of the same basic disease
conditions; b) the latter is probably a low grade selenium poisoning; c) both conditions are associated with repeated attacks of breakdown of red
blood corpuscles, which leads to icterus (jaundice) in severe cases; d) akute attacks are associated with severe fluctuations in copper metabolism; e) there is an hereditory susceptibility factor which determines the disease
incidence and mortality rate in extensive outbreaks; f) sheep which are subject to both diseases, are susceptible from birth
throughout the rest of their lives.
Tests have been devised whereby cases of both diseases may be detected even before any visible symptoms develop. In connection with the effects of the addition of refining stock to peanut oil cake meal, the Research Institute states that refining stock represents approximately 10% of the unrefined oil extract from peanuts processed by the oil cake industry. Such oil cake contain 1% or less fat when processed by heat, pressure and solvent extraction methods. Laboratory tests have indicated that the adsorption of the residual refining stock on the oil cake raises the fat content of the oil cake to 6%. This has resulted in a measurable benefit to lambs fed this cake compared to the use
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of standard cake. It has been suggested that the re -addition should be associated with the inclusion of a synthetic antioxidant to prevent the development of undesirable peroxidation products. This process therefore has the two-fold advantage of improving the nutritional value of oil cake meals and at the same time resulting in a substantial economic benefit to the industry.
With regard to work at Onderstepoort on the effects of lysine, methionine and choline supplementation in growing-finishing pigs it is stated that this is a continuation of earlier experimental work but with the use of ration formulations with lower energy content. In this series there was again measurable benefit derived from the addition of lysine.
Methionine additions however resulted in undesirable changes in terms of
increased backfat, eye muscle fat and feed conversion. Eye muscle area was reduced. These detrimental changes resulted when feeding a ration based on ear maize meal and fish meal, when the methionine was added alone and when in combination with the other amino-acids, lysine and choline. Choline supplementation had neither a beneficial nor a detrimental effect.
(2) Poisoning 1. Mineral Poisoning Many cases of poisoning, sometimes accompanied by heavy morta lities, due to accidental and malicious administration of the caused agents, or the careless use of such materials as salt, urea and anti-parasito remedies, were investigated by State Veterinarians in all the Regions. The Veterinary Research Institute records that it appears that poisoning with chlorinated hydrocarbon compounds is on the increase – twice as many outbreaks were diagnosed this year as during the previous year. Dieldrin is still the most important and most dangerous of these compounds and a special effort should be made to warn the public and especially the farmers of the dangers of this, one of the most frequently used insecticides. An instance is mentioned where a farmer mea Witbank dosed his Jersey herd with Dieldrin instead of a worm remedy and within two days lost 47 out of 120 animals.
Field observations indicate that wild game and specifically the blesbok, are more susceptible to dieldrin poisoning than domestic stock. Two suspicious outbreaks of mortality it blesbok have occurred subsequent to treatment of the gra-zing against harvest termites. The initial concentration on the grazing was only 15 p.p.m. and experimentally it has been proved that hay containing 25 p.p.m. of Dieldrin can be fed to sheep and cattle a year without symptoms of poisoning developing. The possibility of the poisoning being due to a breakdown product, photo dieldrin, is being investigated at present.
Anet faulty or toxic remedies, workers at Onderstepoort found that shortly after registration of a new, very effective broad spectrum anthelminthic, parabendazole, the disturbing discovery was made that this remedy has teratogenic properties when
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administered to sheep, leading to the birth of deformed lambs. This takes place when the remedy is dosed to ewes during the first few weeks of pregnancy. Extensive tests are presently being carried out by die firm concerned to determine the exact effect on animals and in the meantime sale of the remedy has been allowed, with the specific warning that it should not be used in ewes during the first month of pregnancy.
Considerable problems have again been encountered with a certain tope worm remedy for pigeons contaminated with an organic phosphate, leading to extensive mortality in pigeons. It has also been found that certain remedies used in the therapy of biliary fewer in dogs (the diamidiness), can lead to fatal and irreversible brain damage. The nervous symptoms which develop are very similar to those seen in cerebral babesiosis and it has been shown that a number of cases which have clinically been diagnosed as due to the latter condition, were actually due to poisoning by the above-mentioned remedy.
It has been recommended that sick animals be weighed prior to treatment in
order to avoid over dosage and, more important, that if further therapy is required the following day the same remedy is not used but another suitable one.
The Toxicology Section, Onderstepoort reports that during the year 1814
specimens, including 158 plants, were received from 907 sources for toxicological examination.
Of the above, 1662 specimens were analysed chemically, of which 503
specimens from 251 senders were positive for some or other poisonous substance. These positives may be classified as follows:
POSITIVES SENDERS
Arsenic 84 35
Lead 31 12
Salt (Na C1) 14 6
Cyanide (HCN) 20 8
Urea 14 11
Nitrates 7 3
Strychnine 206 118
Aflatoxin 3 2
Parathion 1 1
Water (faulty) 8 3
Dosing 1 1
Remedies (faulty) 36 22
Copper 8 3
Warfarin 2 1
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POSITIVES SENDERS
Dieldrin 52 14
Chlorinated hydrocarbons 11 7
Nicotine 2 2
Manganese 2 1
TOTAL 503 251
Fewer cases of arsenic, lead and parathion poisoning were diagnosed than last year, while the high incidence of strychnine poisoning has been maintained. Research workers at Onderstepoort report that no particular deviations from the normal were encountered in a random test on the chemical pathology, as well as a slaughter test, on animals in South West Africa drinking water condemned on account of dissolved minerals. During the period of observation however, good rains fell and the animals fed on lush grazing, thus requiring less drinking water than during drought periods. The observations will therefore have to be repeated at a later stage. It was remarkable that farmers had relatively few problems with water condemned on all recognised standards and the entire situation will have to be reviewed with a re -evaluation of existing standards. 2. Plant Poisoning From reports received it would appear that the plants responsible for the heaviest losses were Senecio spp. In the Eatern Cape, Natal and Transvaal Regions, tulp (Homeria & Morsaea spp.) in the Natal, O.F.S. and Transvaal; Slangkop (Urginea spp.) in the Eastern Cape, Highveld and O.F.S.; gifblaar (Dichapetalum cymosum) in the Higveld and Transvaal; inkberry (Cestram laevigatum) along the Eastern Cape Coastal area; and vermeerbos (Geigeria spp.) in the O.F.S Region. At the Research Institute, Onderstepoort, a total of 158 plant specimens for identification and/or toxicity tests were received during the year. Generally speaking few problems with plant poisoning were encountered. Thirteen specific plants were tested for toxicity, six of which were found to be poisonous, of which three were new discoveries, viz: a) Kalanchoe lanceolata – a “plakkie” originating from the Kamanjabarea of
South West Africa, which was very toxic to guinea pigs and suspected of having caused poisoning of cattle.
b) Moraea rivularis – a species of tulp from Ixopo. c) Crotalaria sphaerocarpa – a weed which occurs in lands, the seeds of which
were found in maize harvested with a mechanical threshing machine. Large amounts were however required to produce microscopia lesions and the dangers in practice were insignificant.
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Further investigations of similar problems of contamination of grain with Datura
seed (Datura ferox and D. stramonium) revealed that the alkaloid content of specimens received was very low. Poisoning could not be induced in pigs with 5g. of seed per Kg. Of livo weight, mixed in the feed, or with 50g. per Kg. Live weight in sheep in a single massive dose. Pilot experiments have now shown that the main active ingredient of Datura, viz. Atropine, is much loss toxic to animals than hitherto suspected. The first therapeutio effect (N.B. not toxic effect) induced in horses is obtained with 2.5mb/Kg, in pigs with 10 mg/Kg, and in sheep with 50mg/Kg, when the drug is given per os.
The indications therefore are that atropine poisoning and Datura poisoning are
virtually of no importance in domestic stock, while they are of very real significance in the human. 3. Toxins
At the Division of Plant Protection a total of 20 specimens, derived from a variety of animals was examined for pathogenic types of fungus. The specimens were received as animal tissues, swabs or isolated cultures for identification. In the case of tissue or swab specimens, isolates of the type of fungus involved were grown on artificial media.
Four specimens from cases of suspected mycotic abortion were examined.
The fungi isolated were proven non-pathagenic types, according to the literature. No further tests were therefore undertaken with these isolates.
Aspergillus fumigatus is a very common pathogen of poultry, and was found in
the three poultry specimens and cultures examined. Candida species were isolated from three of the four swabs examined. In two
of the three cases the abundance of Candida was due to injudicious use of bacteriostatic antibiotics.
Three fungus cultures of unknown origin were received from private veterina-
rians and identified.
The examination proved that pathogenic fungi do not often play a role in animal health and apparently only appear sporadically.
In Regional Annual Returns only a few isolated small scale outbreaks of
Aflotoxicosis and Diplodia zeae poisoning were reported.
(3) Bacterial Diseases 1. Mastitis
Sporadic outbreaks of “Blue Udder” in sheep occurred during the year and caused severe losses in some instance.
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Mastitis in cattle remained one of the most serious erosion diseases of the
dairy farmer and caused considerable financial losses throughout the country. To be in the position to give the best possible advise on treatment in each
case, antibiogram tests were run at most of the Diagnostic Centres of the Division. This landable effort unfortunately cannot solve the mostitis problem, because it is seldom possible for any State Veterinarian to approach the matter on a herd instead of the individual cow basis, so that results are of a temporary nature, and the disease cannot be eliminated.
The launching of an organised anti-mastitis campaign has so far been
prevented by the serious manpower shortage in both the professional and technical fields.
The Mastitis Laboratory of the Research Institute states that research on
mastitis is aimed at improving udder health in dairy herds. During the past year more than 20 500 milk samples were examined
bacteriologically and cytologically for the diagnosis of mastitis. This work was done on the Onderstepoort herd, four privately owned commercial herds and u number of dairy herds with special mastitis problems requiring veterinary attention. The investigation revealed the considerable extent to which the standard of udder health in herds could be improved by a rational and organised approach to control of mastitis, rather than by attending to clinical cases only. The work has also clearly indicated the deficiencies which still oxist in the application of exesting knowledge on mastitis, by dairy farmers not sufficiently availing themselves of the services of veterinarians.
With the advent of more exacting requirements for mastitis remedies
registered under Act 36/1947, a large number of remedies were not re -registered. These remedies for which registration was recommended, have now proved to be satisfactory and farmers may be assured that these remedies are sterile, non-irritant, in most cases efficient and will no longer contaminate the milk supply with antibiotic rests 72 hours after the final application. Some remedies are excreted from the udder at even shorter periods than 72 hours. 2. Entorotoxamaemia Where farmers conscientiously carry out preventative vaccination according to a regular immunisation programme, few problems were experienced. In some unpretected flocks losses due to Polpy Kidney Disease were severe. The Research Institute issued 43 144 850 doses of vaccine during the year, an increase of 4 620 650 over the previous 12 months. 3. Black Quarter This disease appeared sporadically throughout the Republic. It is gratifying to note that steadily increasing use is being made of the available highly efficacious
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vaccine. Even in Bantu areas owners are slowly beginning to appreciate the value of preventative inoculation. During the year 4 907 886 doses of vaccine were issued. This represents an increase of 27% over the issues for the previous year, which was 35% higher than the figure for 1966/67. 4. “Lamsiekte” Sporadic outbreaks of Botulism occurred in all the Regions, and in a few instances caused heavy mortalities in individual herds. All outbreaks readily responded to vaccination. The Research Institute issued a total of 4 310 445 doses during the year. 5. Corynebacteriasis The incidence of both Corynebacterium ovis , causing lung and gland abscesses in sheep, and C.pyogenes, the cause of abscesses, pneumenia, arthritis and septicaemia in sheep, goats and cattle, is reported to be on the increase. As no reliable statistics are available, it must be borne in mind that this apparent increase could be due to the publicity given to these infections, resulting in more numerous determinations of the organisms responsible. Research workers at Onderstepoort report that success has been attained in the immunization of mice against Coryne-bacterium psendotuberculosis . When mice are challenged with a subacute dose a significant increase in resistance by immunized mice against infection can be demonstrated. This method is suitable for the testing of sheep vaccines and is now used in the standardisation of the vaccine. Extensive experiments on sheep are now in progress to determine the influence of various adjuvants and immunisation schedules on antibody production, It has been established that the bacterial cell walls are responsible for the development of a pretective immunity. This information may load to the development of a significant serological test. Through studies an fractionation it has also been determined that the so-called protoplasmic toxin and the exotoxin are probably identical and not associated with the induction of immunity. 6. Pasteurellosis
Reportis indicate that with the exception of the western parts of the Highveld Region, all areas experienced a decrease in the incidence of this disease.
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The issue of Pasteurella vaccine has shown a corresponding decrease over the last three years. Onderstepoort reports that a survey has shown that Pastearella haemolytica types 1, 4, 6 and 7 are most commonly involved in this disease. These four types, as well as P.multocida types A and D, are at present included in the vaccine. Experiments with this polyvalent vaccine have revealed that it gives excellent protection in sheep and tests in mice show that it is considerably better than that required by international standards. The duration of immunity is however limited and repeated injections are required to maintain a satisfactory level of resistance. Several outbreaks of “sniffles” in rabbits have occurred and special experi-mental vaccine was prepared for the colonies involved. 7. Tetanus Only sporadic cases were reported, and with few exceptions all in sheep. In the majority of instances cases occurred after castration or tail-docking by the illustrator method.
The issue of Tetanus vaccine by Onderderspoort showed an increase of nearly 14% over that of the previous year. 8. Colibacillosis Escherichia coli infections again caused severe losses in young stock, colisepticaemia in lambs and white scours (colibacillosis) in calves being reported from most parts of the country. Very promising results have been obtaining from use of the vaccines. The Veterinary Research Institute states that up to the present a polyvalent live vaccine has been made available to veterinarians only. Due to various problems in production of this vaccine, the possibility of the development of a dead vaccine was investigated. Comparative experiments revealed that the serum of sheep which had received dead vaccine had a higher protective value than that from sheep immunised with live vaccine. Simultaneous administration of fifteen different strains give equally good results. Preliminary results also show that immunity is effectively transmitted from ewes to their lambs. 9. Leptospirosis At the Diagnostic Centre, Stellenbosch, the specimens tabulated below were examined during the year:
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SPECIES NO. OF
SPECIMENS POSITIVE NEGATIVE
Pigs Cattle Sheep Horses Other animals Humans
1,655 8,346 517 156 35 12
398 307 - 41 9 1
1,257 8,039 517 115 26 12
Although pigs, cattle, horses and other animals were found positive to a wide variety of serotypes, not a single instance of any clinical syndrome attributable to attributable to leptospiral infection was encountered. According to a report from the Research Institute, a polyvalent vaccine gave satisfactory serum agglutination titres in guinea pigs, pigs and cattle. Preliminary experiments on a few animals indicated that the vaccine conferred a resistance to infection of about nine months duration. There is serological evidence that besides Leptospira pomona, L.canicola, L.hoys and L.icterohaemorrhagiae, L.bratislava also occurs in pigs in South Africa. 10. Vibrionic Dysentry of Pigs From Natal it is reported that Vibrionic Dysentry appears to have established itself as an important erosion disease of pigs. Infection readily responds to appropriate treatment and adequate hygienic measures. 11. Pseudomonas Infection The Natal Region reports sporadic outbreaks of mastitis and abortion in cattle due to Pseadomonas infection, as well as a uterine infection in one herd of pigs. The cases of “blue udder” and middle ear infection in the Highveld and O.F.S. Regions did not recur this year. 12. Lamb Dysentry (“Bloedpens”) A few sporadic cases of this disease were recorded in the Eastern Cape Region, but it presented no real problem. 13. Actinobacillosis and Actinomycosis Isolated cases of these diseases were reported from the Higveld and O.F.S. Regions. 14. Staphylococcus aureus From the Natal Region it is reported that this organism is the major cause of mastitis in cattle, and in the Dundee area it is often isolated from abscesses in cattle and sheep.
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Research workers at Ondertespoort have found that on repeated administrations of large doses of vaccine, rabbits become immune to skin infections with staphyloc occi. The increased resistance could so far not be correlated with serum antibodies. (4) Protozoal Diseases 1. General The Section Protozoology, Onderstepoort, reports that during the course of investigations on the cause of unthriftiness in 3 to 15 months old Merino and other breeds of sheep, raised in the coastal region of Port Elizabeth and Humansdorp, it become apparent that ticks are active and widely spread on all farms. Biological tests, conduction on sheep with blood collected from emaciated sheep and lambs on one farm showed that they were carriers of Cytoecotes phagocytophila, the causal agent of tick-borne fever and a hitherto undescribed disease in South Africa. Subsequent survays have shown that his parasite may be harboured by sheep in association with Anaplasma ovis, Ehrlichia ovina, and Theileria ovis. The latter four parasites are widely distributed in South Africa and produce anaemia. The sources of the infection could not be established. The causal agent was described approximately 40 years ago in Britain. The frequent importations of cattle and sheep from the British Isles may have included carriers of the pathogen. It is anticipated that the Ixodes sp. and Rhipicehalus spp., commonly found within the coastal regions, are vectors. 2. Babesiosis Redwater in cattle took its usual toll in the Eastern Transvaal, Eastern Cape, Natal and Transvaal Regions, while in the Highveld and O.F.S. sporadic outbreaks were recorded. In Natal, a survey conducted in the area of the State Veterinarian, Greytown showed that 80% of tanks were under strength. A similar situation prevails throughout the Region. This, combined with irregular dipping, has resulted in an increased incidence of Redwater in European areas, whereas a marked decrease has been recorded in Bantu areas, following on the use of more effective dipping materials. According to workers at Onderstepoort the bivalent redwater vaccine will protect cattle against the natural infection of the Europeen (Babesia bovis) and the African (B.bigemina) forms of babesiosis. The period of protection given by the European parasite persists for two years and even longer in contradistinction to that effered by the African parasite which is in many instances less than a year. Expe-rience has shown that the short-lived premunity produced by B.bigemina is boosted periodically when cattle become reinfested with infected Boophilus spp., the chief vectors of this pathogen. On farms where systematic dipping with highly efficient acaracides is practised, it can can be expected that poriodic natural reinfections will
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be diminished thereby resulting in a progressive increase in the number of cattle susceptible to B.bigemina. It is anticipated that the premunity due to B.bovis, in the absence of natural reinfections will eventually terminate in the same way.
Modern chemotherapeutic agents are highly effective in curing both forms of babesiosis. Systematic laboratory and field observations have, however, revealed an important defect in that cattle which have contracted a B.begemina infection after exposure to infected ticks or after immunization are liable to be sterilized after treatment, thus rendering them fully susceptible.
Consideration of the autosterilization and chemosterilization made it apparent that chemoprophylaxis, as practised in some forms of trypanosomiasis with antrypol, antorycide, and aromatic diamidines, may yet be another avenue to be explored for the control of bovine babesioses. Such a chemoprophylactic agent 4 A 65 (Bur-roughs Wellcome) become available. Laboratory tests disclosed that after its sub-cutaneous administration cattle were protected for a period of 3 months against an artificial infection of B.bigemina or B.bovis . Preliminary field trials are being con-ducted to determine the value of this chemoprophylactic agent in cattle exposed to infected ticks.
Biliary Fefer of dogs was prevalent throughout the country, while isolated
cases of Equine Biliary Fever were reported. During the year the project “A clinical pathological study of Babesia canis
infection in dogs” was finalised by a research worker at Onderstepoort as a thesis (University of Pretoria, 1968).
This work offers a broad survey of all important aspects of this infection in
dogs. In view of the variety of symptoms which occur, the action of the disease mainly on the lives, kidneys and cellular elements of the blood was studied in detial.
The large numbers of naturally infected cases presented at the out patients
clinic of the Faculty were utilised as research material and to a lessor extent also artificially infected animals. To determine the effect of the course and intensity of the disease, the animals were divided into three clinical categories.
A wide range of laboratory tests to clarify especially the liver function, kidney
function and the influence of the disease on the different blood cells were carried out and the exact nature and intensity of changes determined by statistical comparison of the figures obtained in the three stages.
It was determined that dogs could die as a result of various causes: medical
shock in cases taking a rapid course (especially in young pups), liver failure, kidney failure and sometimes lung failure. Various combinations of these causes could jointly contribute to mortality, even after the causal organism had been eliminated by appropriate treatment.
The information gained was utilised as a guide to the choice of laboratory
examinations, which could be of value to determine what supplementary treatment
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was essential. In addition the study serves as a model for the basic evaluation of other tropical diseases, a field which requires further study. 3. Anaplasmosis Throughout the Republic, this disease was relatively prevalent. Vaccine issues by Onderstepoort have increased progressively from 246 166 doses in 1965/66 to 460 089 during the current year. Research workers at Onderstepoort state that the value of tetracyclines for the treatment of cattle suffering from Anaplasma marginale and A.centrale are well-known and need not be elaborated on. Tests, conducted during the current year, have shown that the Compound 345-C-61, synthesized by the Wellcome Research Laboratories, England, has a specific action on the two abovementioned Anaplasma spp. when administered intravenously at the rate of 5 mg/kg. The erythrocytic parasites diminish rapidly in number during days after treatment. 4. Besnoitiosis From the Transvaal Lowveld areas a decreased incidence of Elephant Skin Disease is reported. In the Lowveld of Natal it has not spread from the originally affected areas, but the incidence in some herds is as high as 60%. The disease appears to be endemic in the North Western O.F.S. and the adjacent Transvaal districts. Earlier research work at Onderstepoort had shown that strains of Benoitia besnoiti isolated from game animals, gave a very mild infection in cattle, while still protecting against a challenge with the more virulent strains of the parasite originating from bovines. An experimental live vaccine against elephant skin disease in cattle has now been developed from one of these strains. During the year extensive laboratory and field trials have been undertaken to determine the safety and efficacy of the vaccine. It has been found to be quite safe to both sexes and all ages of cattle. Observations on protection covered by the vaccine have not yet been completed. 5. Coccidiosis Sporadic cases in calves, rabbits and poultry were encountered, but no severe outbreaks in any species were recorded. The Research Institute reports that during the past three years three outbreaks of coccidiosis in chinchillas were recorded in Southern Africa; one in the Cape Province, one in Transvaal and in Rhodesia. Considerable economic losses were experienced by the owners in each case. Surprisingly, this disease is unknown in the U.S.A. and Germany where chinchillas are bred on an extensive scale. This led to the suspicion that the causal organism, E.chinchillae might be indigenous to South Africa in small rodents such as rats and mice. Experimentally it has been
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established that at least eight rodent species are susceptible and may serve as sources of infection. The multi mammate mouse and the striped field mouse were found to be particularly susceptible. Both these specious are very common in South Africa and are often found near farm buildings. (5) Virus diseases 1. Blue Tongue Because of the dry early summer months, comparatively few outbreaks occurred. The 22 020 800 doses of vaccine issue by Onderstepoort very closely approximated the issue for the previous year. 2. Horsessichness Very few cases were reported. This was due in part at any rate, to the climatic conditions, which were not conducive to the spread of infection. 3. Heartwater In all the enzootic Heartwater areas, the disease took its usual toll, especially where owners did not take adequate precautionary measures, or relaxed their vigilance. Notwithstanding all modern aids such as curative drugs and effective acaricides, Heartwater remains a limiting factor in successful stock farming in the enzootic areas. 4. Ephemeral Fever In all Regions only sporadic cases of Three Day Stiffsichness occurred, usually of a mild nature, without any mortalities. At Onderstepoort, the study of Ephemeral Fever virus in the electron microscope created problems in the past. Recently, using now methods and chemicals success was attained visualizing the virus in infected tissue culture. This achievement is important for the classification of the E.F. virus and for the study of its biological characteristics. Researchers reports that serological tests were done to investigate a possible relationship between our E.F. virus and the Japanese Bovine epizootic fever virus. Comparative electron microscope studies were also initiated. Both the serological tests and the electron microscopical work indicated that the two virus strains are identical. This fact was also verified by Japanese research workers. It is also stated that an experimental ephemeral fever vaccine has been prepared and is undergoing final tests before it is made available to the public.
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5. Rift Valley Fever and Wesselsbron Disease No cases of these two diseases occurred. 6. “Snotsiekte” Cases of Bovine Malignant Catarrh were confirmed only in the Eastern Cape Region, although unconfirmed cases were reported from other parts of the country. 7. Respiratory Diseases of Poultry In a report on the preparation and testing of a live attenuated vaccine against Infections Bronchitis of fowls, research workers at Onderstepoort state that Infectious brochitis is the most common virus respiratory disease of fowls in South Africa. It causes retarded growth and great losses in egg production. A breeder unit which has experienced a regular drop of 30 – 50 % in egg production over a number of seasons as a result of infectious bronchitis, was used for inoculation of young susceptible pulle ts. The vaccine is an egg attenuated livo virus introduced into the drinking water. The hens tested positively after inoculation and subsequently did not show a drop in egg production. This promising test is being repeated at present on a commercial egg production unit of 50 000 fowls. 8. Fowl Pox As in previous years, this disease occurred widespread. In Natal, a typical form of Fowl Pox made its appearance on two laying plants, miles apart. The symptoms were identical with those of Infectious Laryngotracheitis i.e. gasping, blue combs and numerous deaths. No pox lesions were visible any where. On post mortem, the only lesions were numerous growths in the Larynx, resembling leucosis lesions.
Another peculiar feature was the appearance of the disease during the winter months, while no fowl pox had occurred on either farm at any other time. The outbreak readily responded to a vaccination programme. 9. “Jaagsiekte”
The incidence of this disease was very low, even in those areas where its apparent spread gave rise to alarm in previous years. 10. Virus Pneumonia in Pigs No cases occurred in Natal, where it was reported as widespread during 1967/68, but a small number of cases were recorded in the northern parts of the Eastern Cape Region.
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11. Equine Rhino-pneumonitis Sera obtained from elephants in the Kruger National Park showing small necrotic areas in the genital organs, were serologically positive to Equine Rhino-pheumonitis. Virus particles were also detected by electron microscopy in the sera. No cases in equines were reported. (6) Infertility and Venereal Diseases 1. General State Veterinarians investigated breeding problems in herds and flocks throughout the country, and encountered instances of low fertility and infertility caused by infectious as well as non-specific factors. The personnel of the Artificial Insemination and Reproduction Section of the Diagnostic Centre at Onderstepoort conducted four A.I. courses during the year. The 69 candidates who attended these courses all qualified as inseminators. A total of 91 bulls – 83 at the three A.I. Co-operatives in the Republic – were subjected to tests for fertility and freedom from disease, while the personnel also examined 64 herds with reproductive problems. 2. Vibriosis At the Regional and Onderstepoort Diagnostic Centres 6 613 and 1 624 specimens respectively were examined for Vibriosis. In the former case an incidence of 4.2% was found. As these specimens emanated from herds with infertility problems, this cannot be regarded an indicative of the incidence in the national herd. Nevertheless the disease appears to be more widespread than was anticipated. In connection with the investigation of the breading problems of the 64 herds, mentioned under General above, the A.I. and Reproduction Centre states that it would appear that Vibriosis is the most important single cause of infertility in cattle in South Africa. The Veterinary Research Institute has indicated that the fluorescent antibody test has been standardised to such an extent that it is now utilised as a routine procedure in the diagnosis of Vibriosis in cattle. 3. Trichomoniasis Although this disease has been reported from many parts of the Republic over the years, the incidence is very low and it cannot be regarded as of any great importance.
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4. Infectious Infertility At the Diagnostic Centre at Onderstepoort 1 039 specimens were examined for Infectious Pustular Vulvovaginitis and Infectious Bovine Rhinotracheitis . Of the 1 865 specimens received at the Allerton Diagnostic Centre, 738 were examined in a survey which included the whole Natal Region. Of the 738 specimens, 439 (59.4%) proved positive. The Annual Report from this Region points out that infection is apparently widespread, but clinical manifestation are not often seen. I.P.V./I.B.R. infection was found in 45 of the 64 herds examined by the A.I. and Reproductions Section of the Division. The Section states that the importance of this infection in reproductive problems has still not been established. Workers at the Research Institute report that several thousand specimens of sheep serum were examined by means of complement fixation tests in a survey of the incidence of Brucella ovis and Actinobacillus seminis . The results are still to be analysed statistically, in order to estalish the extent to which these conditions occur in the country and also to indicate the diagnostic value of serological tests. (7) Diseases of Calves 1. White Scours In dairy herds, especially if hygiene and calf management are not of a very high standard, Escherichia coli infection can be of very great economic importance. During the year this disease occurred widespread in all Regions. 2. Paratyphoid In many cases where farmers did not use the vaccine to protect their valves, the disease made its appearance, very often causing considerable financial losses as a result of mortalities or stunted growth. This is one instance where continued efforts must be maintained to actuate farmers to vaccine and so prevent the loss of valuable replacement stock. 3. Coccidiosis Only small scale sporadic outbreaks were recorded during the year. 4. Calf Diphtheria In most Regions only sporadic cases occurred, but one severe outbreak was reported from the Volksrust area of Transvaal. 5. Sweating Sickness In the Eastern Transvaal Region the incidence of this disease was high but only isolated cases were seen in the rest of the enzootic areas.
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(8) Internal Parasites Throughout the year extension work on all aspects of parasite control was maintained although internal parasitism did not assume the usual significance, as a result of the dry conditions during the greater part of summer. Tapeworms in young stock, and round worms and liver and conical fluke were the most important in all Regions. In Natal measles in cattle has assumed alarming proportions; in the O.F.S. Region liver tapeworm has become a major cause of financial loss.
During the year 11 942 feaces samples were examined at Diagnostic Centres, in the course of surveys and diagnostic services to farmers. A total of 117 543 specimens from pig carcasses at abattoirs were found negative for Trichinella spiralis during the same period. In the Kruger National Park T.spiralis was found in 4 hyenas and 1 civet cat. Infection in the latter was unexpected, in view of the usual plant and insect diet of this specie. T.spiralis has now been found in the lion, hyens, jackal, mouse, warthog and civot cat in the Park. In further research work in the Kruger Park Echinococcus cysts found chiefly in the zebra, were fed to a worm free lion, which developed a mass infestation of Echinococcus parasites. Attempts are in progress to work out the life cycle of Pentastomes. Nymphs were found chiefly in the livers of gnu and buffalo, and adults in the nasal sinuses of lion and hyena. The parasite Gramocephalus calcaratus has been found in the bile ducts of the elephant, and it has been established that liver cirrhosis in the giraffe is caused by the parasite Monodentella giraffae. At the Research Institute a new statistical procedure to evaluate worm remedies has been evoled. This method is an improvement on existing procedures as it determines the efficacy of a remedy in the flock as a whole, instead of merely indicating the average reduction in worm burdons in a few sheep only. Research workers at Onderstepoort report that Strongyloides papillosus was found in the intestinal tract of goats after a severe outbreak of mortality. The lesions appeared strange and could not be associated with the parasite concerned as this had always been regarded as a relatively unimportant worm parasite. The purpose of the project was to determine whether Strongyloides papillosis could have played a role in the mortality encountered.
It has been determined beyond doubt that this worm parasite was indeed the cause of mortality in goats and that the lesions observed were actually caused by it. It appears that this parasite is as important as the common bankrupt worm (Trichostrongylus species) and that it is also fetal to sheep.
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(9) External Parasites Climatic conditions in most areas were not conductive to flourishing tick life. Major problems resulting from heavy tick infestations were therefore not often encountered. The paralysis tick is reported as causing concern in the Southern and North Eastern Free State. Thousands of ticks and a large number of dip samples sent by officers of the Division in Natal, were examined by the Tick Investigation Centre at Onderstepoort. With rare exceptions, no cases of the resistance of ticks to the newer acaricides were found. A very high percentage of dip samples, however, proved to be under strength. Keds, sheep nasal fly, Australian itch and sheep maggots caused no large scale losses but lice in cattle in the Bantu areas and sheep lice in the East Griqualand area of Natal created problems. It is also reported that in the North Western Cape areas of the O.F.S. Region sand tampans are on the increase and steadily spreading to areas previously uninfested. At Onderstepoort investigation into the incidence of resistance to acaricides was continued. It appears that the blue tick (Boophilus decoloratus ) in Natal does not possess the same degree of resistance as those in the Cape East. Investigation has further revealed that the young, partially engorged female presents a stage in the life cycle in which it is susceptible to certain dips. A Survey of dip samples in Natal has revealed that 80% of dips in that area are applied at “under strength”. A total of 608 dip samples were analysed during the year. Research workers at the Institute report that in a study on saliva production mechanical removal of female Amblyomma hebraeum ticks, embedded in sheep, was performed throughout the engorgement period. By exercising slow and gentle traction with the aid of a pair of four-inch curved dissecting forceps, ninety five per cent of the ticks were removed with the mouthparts intact.
To ensure complete and even engorgement of all the females, the presence of an equal number of males, placed on the host a week before allowing the females to feed, is essential.
Induced saliva production of engorged and semi-engorged female ticks, removed mechanically, was successfully carried out by the injection of 0,2% Pilo-carpine subcutically in the region of the central ganglion in a room at 30 - 33°C. Fully engorged recently detached females also yielded saliva, but the production de-creased markedly in females detached for several hours with no response from ticks detached for a few days. Optimal production was achieved during the period of maximum engorgement. The average saliva production of female Amblyomma he-braeum ticks is significantly higher than that of Ornithodoros savignyi.
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The experiment is a prelude to a proposed project to determine the presence of Rickettsia ruminantium in the salivary glands and salivary secretions of Amblyomma hebraem. The Entomology Section of the Onderstepoort Institute states that a survey is being carried out on farms in the Bethulie, Smithfield, Albert, Venterstad, Philippolis and Colesberg districts. The aim is to determine the tick species and populations occurring now for comparison with those present later when parts of the area have been flooded. In other words, it is an attempt to gauge the effect of the dam on the local tick species. Work on the project began in January 1969, when a Stock Inspector from the Division of Veterinary Services was posted to the area to make the necessary collections. These are subsequently identified at the Veterinary Research Institute, Onderstepoort. Thirty-three farms have been included in the survey to date, on which the initial series of collections was completed by the end of April. The second series is now being made. It is intended that four collections will be made on each farm during the year covered by the survey.
Ticks have mostly been collected from cattle and sheep, plus a few horses. The following species have been obtained to date: Otobius megnini; Hyalomma marginatum rufipos, H.truncatum; Ixodes rubicundus; Rhipicephalus capensis, R. evertsi evertsi, R. glabroscututum and R. pravus. Of these O. megnini appears to be the commonest species, recorded on the majority of the farms. H. marginatum is also widespread. R. capensis, R. glabroscutum and R. pravus have rarely been obtained so far. Adults of I. rubicundus were completely absent from the initial series of collections; they make their first appearance in the latter half of May. The chemical control of Ornithodoros savignyi by the application of insecti-cides on the sand, was investigated in the field in July 1968. Of the ten most promi-sing insecticides tested only Baygon 20% E.C. at 0.5% and Karbadip W.P. at 0.15% of the concentration were found to be of any value, giving a 72 and 68 per cent kill respectively. Tampans were stimulated to come into contact with the insecticides on the surface on three occasions.
Further insecticidal tests were conducted in the field in April 1969, using Folimat 50% E.C. (Agrochem) at 0.1%, Dieldrex 15% E.C. (Shell Chemicals) at 0.1% and Baygon 20% E.C. (Agrochem) at 0.03% of the active ingredient. Baygon was applied at a significantly lower concentration than in the previous experiment. On account of the long residual properties of Dieldrex and Baygon, the efficacy will only established after the lapse of several weeks.
Of significance is that tampan emergence is temporarily inhibited by the wet
sand, due to reduced sand temperatures following insepticidal application. But the insecticides themselves have a marked influence on tampan emergence, either be-cause the tampans are killed or because they avoid coming into contact with the insecticide in the superficial layers.
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The fumigant, Phostoxin tested against tampans in both the laboratory and in
the field, proved to be useless. In connection with the possible use of gallinaceous birds as a form of biolo-
gical control against Ornithodoros savignyi, a study undertaken during April 1969, has shown sand tampans are avidly eaten by fowls wherever they encounter them. In one instance a New Hampshire hen with six chickens utilised, within minutes, se-veral thousand tampans, comprising all the different stages, without showing any harmful effects.
Surveys conducted on three farms where gallinaceous birds are present and
which are allowed to roam in and around kraals, have shown that tampans were not a problem or a serious hazard on these farms. There are indications that studies on the population structure of tampans may yield valuable additional information in relation to biological controlling mechanisms.
Several farmers have specifically acquired gallinaceous birds, particularly
bantams and domestic guinea fowls, to control tampan populations on their premises.
The results obtained, justifies a thorough investigation in the role played by gallinaceous birds in the control of tampans. This requires detailed and extensive surveys and a thorough knowledge of the structure, dynamics and density of the tampan populations in relation to biological controlling mechanisms. An experiment to determine the effect of gallinaceous birds introduced into a heavily infested tam-pans region should be conducted.
In connection with the resistance of the sheep blow fly to insecticides in the
Riversdal area, the Research Institute reports that during November 1968 a com-plaint was received that sheep blow fly in the Riversdal district could no longer be controlled by using the recommended concentrations of insecticides. After a visit to the area specimens of the primary blow fly of sheep, Lucilia cuprina, were collected and bred in the insectarium at Onderstepoort.
In comparative insecticide tests with a local strain of L.cuprina, which had
been bred for years in the insectarium for biological tests and which had never been in contact with insecticides, it was found that the Riversdal strain did show resis-tance.
Nine different insecticides were used against the two strains and it was found
that a resistance varying from two fold to a hundred-fold could be determined in re-spect of the Cape strain. Wool samples from treated sheep in the Riversdal district were also used against the two strains and it was found that the Riversdal blow fly could be controlled for only nine weeks against double dipping strength instead of the normal 35 to 38 weeks.
As regards the midge problem in the Vaalharts Irrigation Complex, research workers state that in the past it was found that the application of insecticides in the Vaal river for the control of Simulium, strongly promoted the growth of certain algae
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which then overgrew the rocks and submerged plants in the river bed. As the colume of water rose after copious rains, these mats of algae disappeared. Due to the drought conditions of the past year the algae persisted and even increased consi-derably, since the previous campaign against Simulium terminated in January 1968, to such an extent that this seriously hampered the establishment and development of the insect. The young aquatic stages of the simulium were unable to establish them-selves on the submerged rocks as a result of the covering of slippery, clay-like depo-sit, while the dense mat of thin filaments apparently filtered out the organic and clay-bound particles forming the source of food for the larval stage.
These unnatural conditions effectively control the Simulium population, as
their incidence is at present still very low, 18 months after the last campaign. The algae evidently have a strongly retarding influence, expecially on S.shutteri which forms the main problem in the area, while S.damnosum which is of lesser veterinary importance seems to thrive. The altered conditions clearly reveal the adaptability of the former species, at check points with a receding prevalence of algae: Check piont S.chutteri S.damnosum
15 miles (1. Witrand (algae prevalent) 10% 90% (2. Windsorton (few algae)) 94% 6% 50 miles (3. Gong Gond (no algae)) 100% 0%
Further, in a survey of the Simuliidae of the Orange-Caledon Rivers system,
sampling of the Orange River complex of dams in preliminary survey has indicated that certain species of Simuliidae do occur there. The area involved included the two rivers, the Orange and Caledon, as well as the three dams under construction, Ver-woerd, P.K. le Roux (van der Kloof) and Torquay, over a total distance of 300 miles. The species S.grissicolle was encountered throughout the entire area and sometimes at a surprisingly long distance from the rivers or any streams. This species is a bloodsucking parasite, more particularly of birds, in preference to other animals or humans, but has a flight distance of more than 50 miles and is not to the same extent as S.chuteri dependent on plant growth for its distribution. Where the rivers were sampled for the immature stages of the midges, S.chutteri was also encountered in low concentrations. That portion of the Orange river below the Torquay dam is very suitable for this species, and it may create a problem at a later stage. 4. OTHER VETERINARY RESEARCH (1) Basic Research 1. Isolation of Haemophilus gallinarum This technique for the confirmation of the clinical diagnosis of this important disease, was developed at the Institute. Hitherto it was not possible to utilize this technique as a routine procedure.
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An accurate bacteriological technique has been evolved, which proved to be 100% effective when applied to 90 individual cases showing early symptoms. In each case the disease could be transmitted with isolates, 18 – 48 hours after infec-tion. This technique could be of immense value to diagnostic laboratories, parti-cularly as Heamophilus produces symptoms very similar to those of Mycoplasma gallisepticum, the latter being a serious condition which requires early elimination for effective control. 2. Chemotherapy of Haemophilus gallinarum The efficacy of various drugs against this bacterium was tested. An unregi-stered sulphonamide proved to be 75% effective, compared with two broad spectrum antibiotics which were 12% and 0% effective, respectively. 3. Isolation of Mycoplasma synoviae Chicks showing retarded growth and general arthritis and tendo-vaginitis were found on one of the biggest poultry farms in South Africa. Investigation revealed the presence of infectious sinovitis. This disease was previously unkown in the Republic. A search for the causal bacterium was conducted. A mycoplasma which differs serologically from M.gallisepticum was isolated and the same disease as occurring naturally could be produced by this organism. This organism somewhat resembles on imported strain of M.synovisae, but there may be slight serological differences. An antigen to diagnose the disease serelogi-cally has been prepared in small quantities. 4. Bone Pathology in Brioler Chickens An interesting abnormality of the bones, which is assuming serious propor-tions, is being studied in broiler chickens in certain Transvaal and Natal production units. The condition may be described as an abnormal proliferation of certilage in the epiphysial area of the distal femur and proximal tibia leading to thickening of the joints torsion and fractures. It is observed in dayold chicks and the incidence in-creases with increase in weight o f the animals. The condition up to the present could not be corrected with diet and is often correlated with accompanying leucosis. 5. A comparative Physiological Study of Red Blood Cell in the Sheep and
the Dog With the object of gaining more information on the basic changes associated with the syndromes of “geel dikkop” and enzootic icterus, the transport mechanism of various substances through the cell wall of red blood cell was studied. No real difference could be demonstrated between recovered cases and clinically healthy sheep. In the case of sheep subject to the two syndromes or in the recovery stage of the diseases, marked changes were observed. Differences in the
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calcium content and fatty acid composition of the cell wall may be regarded as characteristic. Furthermore the mechanism controlling the volume of the red cell is largely broken down, resulting in increased fragility, of the red blood cell. There is a clear connection between the degree of damage to the red cells and the haemoglobin genotype present in these cells. The results obtained showed definite functional advantage of the A fenotype compared to the B fenotype, that is, the former is able to overcome the factors associated with “geel dikkop” and enzootic icterus more readily than is the case with the B fenotype. These results are of direct importance in the future breeding programmes which should be instituted in an attempt to increase the percentage of A fenotype sheep. 6. Sterility in a Bull, Co-Twin to a Freemartin An infertile bull with bilateral hypoplastic subcutaneous testes and co-twin to a “freemartin” is described. When killed at 21 months of age it had a chimeric ratic of 77 per cent 2A-XX cells versus 23 per cent 2A-XY cells in its haemopoietic tissues. Although alluring, chimerism cannot be accepted without further evidence as the primary etiological factor of the incomplete testicular descent. Adrenocortical and hypophyseal changes indicating a hormonal imbalance and the possibility or a fortuitous coincidence of a genetically determined cryptorchid are complicating aetio-logical factors. This is the first case on record of sterility in the male co-twin of a freemartin. 7. Preservation of Ram Semen Experiments have been conducted on the addition of varying percentages of gelatine to the diluents for rams’ semen. The results obtaining appear promising for short term preservation of 2 to 5 days. These results could be of great value to the growing Artificial Insemination industry, particularly to sheep breeders applying oestrus synchronisation to their ewes. 8. Vibriosis and Trichomosiasis Preliminary field tests with treatment of vibriousis and trichomoniasis have yielded promising results. In the case of Trichomonas the drug Emtryl was used. 9. Studies on the Morphology of Sperm These studies, particularly on the shape of the sperm head, have revealed that the size of the sperm head remains constant with long terms semen collections. 10. Researches on the Digestion and Metabolism of Ruminants A study is being made of the digestion of high roughage diets and the meta-bolism of the digestive end-products of these by Merino sheep. This is because large areas of the Republic of South Africa are suitable only for pasture production.
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Compared with the monogastric animal, the ruminant is an inefficient converter of protein and energy into meat and wool. It cannot, therefore, in the long run, be allowed to compete for the limited amounts of concentrated foodstuffs which can be grown. Rather, use should be made of the ruminant’s unique ability to convert the fibrous components of roughage and non-protein-nitrogen compounds like urea and biuret, into energy and protein. Since the ruminant can make use of these only with the aid of the bacteria in its rumen, these micro-organisms are being investigated to determine what species are present, how they are affected by the diet of the animal and what end-products they make available as a result of their fermentation of the food. Because any carbohydrate in the diet is broken down largely or completely to volatile fatty acids by the bacteria, the carbohydrate and energy metabolism of the animal itself differs in many important respects from that of a monogastric animal. A study is, therefore, being made of the metabolism of the host animal and the use it makes of the end-products of rumen fermentation. There is a physical limit to the amount of roughage the rumen can contain at a given time. Thus the daily intake depends largely upon the rate at which it can be digested. Previous work showed that supplementatin of poor teff hay (3-4% crude protein), first with urea and then with branched-chain volatile fatty acids, increased the levels of the fibre-digesting rumen bacteria, and enabled the more active species of these to predominate. This resulted in a 50% increase in the daily roughage intake which allowed 80 lb – sheep almost to maintain their weight on the supplemented diet, whereas they had lost 1 to 2 lb weekly on the hay alone. Thus by designing the diet to supply the needs of the ruminal flora, those of the host animal were also automatically supplied. This constitutes an entirely new concept in ruminant nutrition and applies particularly to high roughage diets fed ad libitum. Studies with the Kistner continuous culture system have shown that to encourage a rapid growth rate of the most active fibre-digesting species, it is not necessary to add all the relatively costly branched-chain fatty acids at 2% level, but only one of them at less than 0.1% level. The mechanism by which biuret can be used as a non-toxic substitute for urea in the supplementation of high roughage diets has been extensively investigated. Using radio-biuret, it was conclusively shown that biuret, as such, is not metabolised by ruminant tissues, but is broken down quantitatively to ammonia by biuret – splitting bacteria in the rumen. The growth rate of these bacteria under most practical dietary conditions enables them to break down the practical amounts of biuret eaten by ruminants within the first 2 or 3 days of feeding biuret. To maintain the necessary high numbers of these bacteria, there must be no interruption in the daily intake of biuret and a 10% starch supplement should be added to the diet. Owing to the bulky nature of high roughage diets, it happens, particularly in ewes on range and in the last month of pregnancy, that the space occupied by the unborn lamb limits the space available for the ingested roughage. Thus, the ewe tends to be chronically short of energy at least, just at a time when her need is greatest. Thus a balance sheet of the various sources of energy to the ruminant on different planes of nutrition is being drawn up. Results have already made it clear
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that sources of blood sugar to pregnant ruminants on range in the Republic are critical and that insulin plays a decisive role in controlling metabolic upsets in under-nourished pregnant ewes. 11. The Response of the Bovine Adrenal Cortex to Halothane Anaesthesia
The purpose of this investigation was to determine to what extent halothane anaesthesia affects the adrenal cortex. The concentration of cortisol, blood sugar, sodium, potasium together with a complete blood picture, was determined. The changes encountered, indicated that halothane anaesthesia should be regarded as a stress factor. Important differences were encountered between various breeds, which justifies further investigation. 12. Properties of Bluetongue and Horsesickness Viruses
Continued research on the basic properties of these two viruses has revealed that as far as size, appearance and physical properties of the virus particles are concerned, they are indistinguishable from each other. Both viruses have a double stranded ribonucleic acid nucleus, a property which distinguishes them from all other known animal viruses, but places them in the same group as a few viruses originating from human and plant sources. Onderstepoort has proposed that these viruses should be grouped together and this has attracted considerable attention in overseas countries.
The influence of these viruses on the cells of susceptible animals, is being
further investigated by chemical methods as well as electron microscopy. It has inter alia been found that the virus of blue tongue causes the formation of a virus repellant substance, called interferon, in the cells. This research is being carried out in order to gain more knowledge on the changes taking place in the animal body infected with virus and in this way possibly finding better methods of control. (2) Miscellaneous Research and Projects 1. Various projects, in many State Veterinary Areas, were initiated, continued or
concluded in efforts to establish the most urgent or most important problems facing stock farmers of the area, and evolve solutions.
2. In the Queenstown Area efforts were continued at evaluating different regimes
for administering various anti-parasitic remedies, to enable the best possible recommendations to be made to all farmers in the Area, whatever their husbandry practices.
3. The registered project on investigation into the various aspects relating to ill
thrift of sheep in the Port Elizabeth area, was continued.
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4. Work on the project re Geeldikkop and Enzootic Icterus is continuing at
Middelburg, C.P., where various aspects of Actinobacillus seminis infection in sheep is also being investigated.
5. Two projects were completed during the year. One, registered at Beaufort
West, dealt with the seasonal incidence of internal parasites in Karoo areas, while an evaluation of Coryne bacterium pseudotuberculosis ovis vaccine was carried out at Middelburg, C.P.
6. At Mafeking investigation into various aspects of Rabies, including the ecology
of viverridae, was continued. (3). Research on Disease of Game In the Kruger National Park topographical anatomical studies of the elephant revealed that the brain is small (0.21 – 0.25% of body weight) and is encased in a “box´of bone lamellae which serve as anti-shock apparatus. Also, the lungs are adherent to the ribs and cannot deflate as in other animals. Investigations into typing of blood samples was continued. It would appear that herds of buffalo in the Central Area show different reactions to those of the Southern Area, indicating that these herds reproduced and multiplied on their own, without any mingling even during the breeding season. The Skukuza Abattoir and By-products Plant is used for processing elephant, buffalo, gnu and impala carcasses. Meat fit for consumption is made into biltong. Other meat is processed into meat meal, while all bones are converted into bone meal. Samples of biltong, carcass meal and bone meal are bacteriologically tested to exclude salmonella contamination. Animal carcasses inspected at the abattoir are listed below:
Approx. total Species No. of carcasses Carcass Weight
The Zootechnology Department of the Veterinary Research Institute reports as follows: Cattle: With the co-operation of a Belgian scientist last minute preparations were made prior to the final allocation of blood grouping reagents to the laboratory at
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Irene. This entailed a full re-immunization program to restore depleted stocks due to the change-over. International comparison tests are still centred on the Institute and the 1969 U.S.D.A. (United Stated Department of Agriculture) – test was finalized at Onderstepoort during May 1969. Horses: Production of blood grouping reagents was continued on a large scale, making use of horses at the Faculty and at Kaalplaas. Many new blood factors were found and reagents produced. The 1969 comparison test was carried out by the French laboratory at the Louis Pasteur Institute and proved that at least 27 blood factors could be identified with the reagents produced at Onderstepoort. The main purpose of this work will be a contribution to the problem of haemolytic icterus in newborn foals. Sheep: Work on the haemoglobin types in sheep continued and at this stage it can be stated that stock breeders and wool producers in the areas where Geeldikkop is prevalent should select and introduce rams possessing haemoglobin type A in order to increase the frequency of haemoglobin A in their flocks. In doing this, losses due to Geeldikkop and enzootic icterus could be decreased considerably. Furthermore, investigations have been initiated to study the relationship between serum transferring types and brucella abortus infections in large flocks of Karoo-sheep. Goats : Together with blood samples from Angora goats in outlying areas, use is being made of local Angoras in an attempt at eludicating the cause of the high abortion rate. Blood group antibodies have been produced against goat erytrocytes using sheep as recipients, thereby producing antibodies of very high titres. The immunogenetic pattern of Angoras has been compared to that of Boerbokke and Kaffirgoats as a control. Wild Animals: With the co-operation of the Parks Board, investigations were carried out on rhino, zebra, buffalo and elephant in an attempt at immuno-haematological classification. Together with the Karyo-types of these animals, it is hoped that a more comprehensive picture can be obtained of the migratory habits, mortality and reproductive rate of these animals, factors of primary importance in nature conservation and of basic importance to Veterinary Science. 5. VACCINE PRODUCTION
During the past year a total of 108 802 416 doses of 27 different vaccines was issued by the Institute. The total book value of these vaccines amounts to R1 703 369,52. The vaccine figure represents an increase of about 0.2% on the previous year’s total. This slight increase creates a wrong impression in that the demand for Newcastle disease vaccine decreased by 11 million doses, after the successful control of the outbreak in the Western Cape. If one disregards the issues of Newcastle disease vaccine to the Division of Veterinary Services, the demand for all the other vaccines shows a phenomenal increase of 12.7% to a total of more than 100 million doses.
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The trend of vaccine utilisation shows the following: The demand for bacterial vaccines, especially enterotoxaemia, botulism (lamsiekte), Anthrax, quarter evil and brucella vaccines has increased on average by 14.8%. Although the total demand for vaccines against virus diseases shows a decrease on account of the drop in Newcastle disease vaccine, the actual increase in issues of the other vaccines such as blue tongue, fowl pox, distemper and Rift Valley fever represents about 8.4%. The great increase in demand for Rift Valley fever vaccine was due to outbreaks of this disease occurring in the neighbouring countries Rhodesia and Mocambique. The demand for heartwater blood and redwater and gallsickness vaccine increased by 12.8%. The number of doses of the different vaccines issued during the year under review, are shown in the attached table. Apart from vaccines, the Institute also prepared and issued other biological products such as tuberculin and test antigens, as indicated in the table. These issues increased by 55%.
At the Diagnostic Centre, Stellenbosch, 17 700 ml. of Leptospirosis antigen (11 different strains) was prepared. 6. OTHER VETERINARY SERVICES (1) Diagnostic Services
As indicated in the Introduction, Regional Diagnostic Centres are being streamlined as far as possible. Greater utilisation of these Centres would have a two-fold advantage. In the first instance, it would ensure that Onderstepoort is relieved of the greater part of routine diagnostic work, thus enabling the Institute to devote its time to basic research and to diagnostic work of a more advanced nature, requiring specialised techniques or facilities. Secondly, a decentralised diagnostic service, with Centres placed strategically in the various regions of the country, ensures a more rapid and satisfactory, diagnostic service to stock owners. Apart from conducting campaigns against several scheduled (notifiable) diseases, State Veterinarians at Diagnostic Centres and other stations investigated mortalities and disease problems, and were engaged in veterinary extension work,
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the implementation of disease eradication programmes and schemes, and co-operated with the Research Institute in research projects. State Veterinary Officer and Regional Diagnostic Centres reported carrying out the post mortems listed below:
Biopsies 257 Bone meal 176 Clostridia 134 Foetus 71 Organ and Swab 3 269 Poultry 3 211
(2) Surveys
The survey to determine the distribution, incidence and significance of Actinobacillus seminis infection in sheep, commenced during the previous year in the Highveld, Eastern Cape, Natal, O.F.S., and North Western Cape areas, was continued during the year.
A sterility survey conducted in selected herds in the Pietersburg district of the
Eastern Transvaal Region has clearly indicated that poor grazing and feeding conditions play a greater role than genital diseases in the average calving percentage of these herds.
In several districts of the Highveld Region a survey to determine the
distribution of I.P.V./I.B.R. infection in cattle was launched. Preliminary reports indicate a high percentage of infected herds.
In the Mafeking district the finding of Amblyomma hebraeum on cattle from
certain farms during a tick survey, points to a further westward spread of this species.
Investigations were conducted into the seasonal variations of the mineral
status of cattle on selected farms in the different ecological areas of the Natal Region. Valuable information has already been obtained, and in some instances remedial measures have produced spectacular results. The survey is continuing.
The average calving percentage in 197 dairy and 101 beef herds in the Natal
Midlands was found to be 76 and 63 respectively, in a survey of bovine fertility conducted in connection with a registered project.
In collaboration with Onderstepoort, the State Veterinarian, Nongoma, sent in
a large number of blood specimens from cattle in the areas adjoining the Hluhluwe-Umfolozi Game Reserve complex, in a Corridor Disease survey, which has not yet been completed.
Determination of the incidence of mastitis in cattle has commenced in certain
Natal State Veterinary Areas, and this is to be continued and extended. The annual Nagana survey in Natal, in the areas previously infested with
tsetse flies, was carried out, and the position found satisfactory. In the area of the State Veterinanrian, Ixopo, the scope of the survey of
poisonous plants was further extended.
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In the O.F.S. Region preliminary indications are that peri-natal mortality in
lambs is more closely associated with management and husbandry practices than with any specific diseases. Due to lack of professional staff and facilities, however, progress in this survey has been slow, and no final conclusions can be drawn from the data collected.
In the Transvaal Region, surveys have been initiated for the investigation of
sterility in sheep and cattle, and peri-natal mortality in sheep. In the Bredasdorp district of the Western Cape, copper and manganese
deficiencies have been shown to exist, in investigations carried out over a period on 32 farms.
From 10 farms in the Vredendal district a total of 115 liver and 88 blood
specimens and from 18 farms in the Paarl district a total of 31 liver and 169 blood specimens have been analysed, but these surveys have not been completed and no results are available as yet.
At this stage of the investigations into peri-natal mortality of lambs, no results
have become available. The project is being continued in the Western Cape Area. (3) Clinical Services In all areas where there are no private veterinary practitioners available, State Veterinarians provided clinical services when the time was available for doing so. During the year R13 031,25½ was collected for clinical services, R5 514,55½ for mileage fees and R13 403,58 for vaccines sold by State Veterinary Offices. (4) Artificial Insemination Services
For the registration of new bulls intended for A.I. service, and for the re-registration of bulls standing at the A.I. Co-operatives and individual breeders, a total of 91 bulls was examined by the A.I. and Reproduction Section of the Division.
All the 69 candidates who attended the four A.I. courses held at Onderstepoort
for persons desirous of registering as inseminators, were successful in passing the examination.
In addition to the above, the A.I. Section also presented a short course on A.I.
in sheep to 15 farmers at Neudamm in South West Africa, and gave lectures and demonstrations at 5 Farmers’ Days and meetings of Farmers’ As sociations.
At Potchefstroom 21 A.I. courses were presented to farmers who wished to
carry out A.I. in their own herds. These courses were attended by 285 farmers. Well attended courses for small groups of interested persons were also
presented at Allerton, Ixopo and Vryheid in Natal.
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Although there is a demand for A.I. courses at Glen and Upington in the
O.F.S. Region, this cannot be met as a result of the absence of the necessary facilities. 7. HEALTH SCHEMES (1) Bacillary White Diarrhoea
The data tabulated below shows no appreciable change from the previous year in the total number of certificate holders. Because of the outbreak of Newcastle Disease in the Transvaal Region, the number of holders decreased from 78 in 1967/68 to 56, but this was almost off-set by the resumption of testing in the Western Cape after the eradication of Newcastle Disease in that areas, which resulted in an increase in certified flocks from 1 to 16.
(2) P.P.L.O Scheme As a result of the Newcastle Disease outbreak in the Transvaal Region, only a few flocks could be tested during the year. Testing was resumed in the Western Cape, but several flocks that had been negative prior to the Newcastle Disease outbreak in that Region, now proved positive, and it may take months of intensive testing to eradicate infection. The data of tests performed is summarised below.
Certificate Holders Non-certificate Holders Region Number Number of Birds Flocks Number of Tests
(3) Pig Recording and Health Scheme No spectacular expansion of this scheme can be reported. Membership increased from 31 to 37, with a total of 15 898 pigs involved. 8. MEAT INSPECTION
Meat and meat products intended for export were inspected at packing plants, the Johannesburg abattoir and the bacon factories at Estcourt, Heidelberg (Tvl.) and Durbanville.
During the year two Regional Meat Hygiene Officers were appointed, one for
each of the Natal and Winter Rainfall Regions, in anticipation of the implementation of the Animal Slaughter, Meat and Animal Products Hygiene Act of 1967.
All plants producing bone, blood, carcass or fish meal were inspected prior to
registration or the annual re-registration under the Fertilizers, Farm Feeds, Seeds and Remedies Act, 1947 (Act No. 36 of 1947). 9. STOCK INSPECTION SERVICES Once again a large proportion of the inspectorate staff of the Division was of necessity seconded for lengthy periods to special duties on the Newcastle and Foot and Mouth Disease campaigns. In the majority of areas not directly affected by these two diseases, only a skeleton staff was left to cope with routine work and all possible eventualities.
The fact that the Division was able to conduct successful eradication campaigns against serious epizooties, while maintaining precautionary short interval inspections in the border areas of the Republic and all other essential services in the rest of the country, certainly underlines the indispensability of the inspectorate personnel of the Division to the protection of the health of the national stock population.
It must be mentioned here that Bantu Assistant Stock Inspectors are doing excellent work in many non-white areas , where it is often impossible to station white officers. The substitution of non-white for white officials has the added advantage of making available white Assistant Stock Inspectors to fill some of the increasing number of vacancies in white areas due to retirements and resignations, which cannot be filled on account of the tardy recruitment resulting from the poor inducement offered by the existing salaries.
10. ANIMAL HEALTH EXTENSION SERVICE Sound scientific stock farming practices are essential, not only to the individual farmer, but also to the national economy. The Division is aware that a high percentage of farmers do not fully utilise the accumulated mass of scientific knowledge available, and strives to remedy this by all the means at its disposal.
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During the year lectures on a wide variety of veterinary subjects were delivered to farmers’ groups; film shows, usually accompanied by short lectures, were presented; study group meetings were initiated or continued; pamphlets were drawn up for distribution directly, or indirectly through inspectorate personnel, to farmers; articles were written for the local press and national agricultural journals; contributions were delivered for the “Calling all Farmers” radio programme; in office interviews and during visits to farms State Veterinarians did very valuable and very effective, even if not very spectacular, extension work. 11. IMPORT AND EXPORT CONTROL (1) Import
One of the important functions of the Division of Veterinary Services is the control of the importation of animals, products and any other materials that could introduce animal diseases into the Republic. The animals listed below were imported for slaughter, farming or other purposes:
In accordance with the requirements of the importing countries, veterinary examination and certification was undertaken in respect of the undermentioned animals presented for export :
The training of veterinarians adequately equipped for the handling of stock disease problems in the country was continued. During the past number of years 45 students per year were selected for entry to the second academic year in the Faculty of Veterinary Science. Because it is generally realised that as a result of this restriction the number of veterinarians qualifying is insufficient to supply the requirements of the country a Committee of Enquiry was appointed by the Honorable the Minister of Agriculture to investigate the training of adequate numbers, in all its facets. The recommendations of this Committee are now being awaited.
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As the Faculty is at present an integral part of the Department of Agricultural
Technical Services, a Committee has also been appointed by the same Minister to determine whether the status quo should be maintained or whether it should become a fully fledged university faculty.
Teaching in surgery returned to normal during the year on completion of
building alterations and additions to the existing building. These comprise clinic halls for horses, cattle and dogs, an additional bovine
hospital stable, a new section of radiology with the most powerful clinical diagnostic apparatus available and four new operation theatres with modern equipment; one large animal theatre, two for small animals and one student theatre with six operation tables.
Surgical cases treated during the year included 1 312 dogs, 183 cats, 106
equines, 144 cattle, 51 small stock, 13 pigs and 6 birds. The Department of Medicine of the Faculty of Veterinary Science dealt with a
total of 244 in-patients and 6648 out-patients. The latter figure includes cases treated by the ambulatory clinic. In addition, 6958 clinical pathological specimens were examined.
The numbers of students undergoing training at the Veterinary Faculty,
Onderstepoort, are set out below:
B.V.Sc. II 45 B.V. Sc. III 46 B.V.Sc. IV 43 B.V.Sc. V 43 Dipl. Veterinary Public Health 2 M. Med. Vet. 18 D.V.Sc. 7
During the year 36 students obtained their B.V.Sc. degrees, while 3 M.Med. Vet. And 2 D.V.Sc. degrees were conferred. (2) Other Veterinary Training
As in previous years, State Veterinarians were responsible for teaching veterinary subjects for the Diploma Course, at the various Agricultural Colleges.
At the Bantu Agricultural College at Fort Cox the veterinary course for Bantu
Assistant Stock Inspectors was conducted by the State Veterinarians, East London. The State Veterinarians, Pretoria, were actively engaged in the teaching of
veterinary subjects to trainees in the basic course for Agricultural Field Technicians.
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As a result of the second-ment of so many members of the inspectorate
personnel to special campaign duties for lengthy periods, in-service training did not receive the required attention. This applies to both informal and formal training.
In respect of the latter, progress could be reported in connection with the
compilation of manuals for the various ranks of inspectors. These manuals are intended as a guide to officers in their normal work also, but mainly as a basis for lectures in the envisaged intensive formal in-service training courses for all ranks.
TOTAL 11 097 405 27 263 143 7 711 696 4 923 960 314 507 224 536 944 878 22 332 302 956 362 28 721 * Please refer to next page for analysis of cattle figures.
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Distribution of Cattle
Region White Owners Non-White Owners White Areas Non-White Areas White Areas Non-White Areas
Cape East & Karoo 675 328 6 827 37 772 172 286
Eastern Transvaal 385 180 5 614 61 983 457 976
Highveld 2 778 276 52 173 713 111 432
Natal 1 025 820 2 380 289 588 1 246 018
O.F.S. 1 136 588 897 7 204 117 362
Transvaal 1 697 538 950 173 398 250 864
Winter Rainfall 277 615 - 4 389 425
TOTAL 7 976 345 16 720 748 047 2 356 363 14. PUBLICATIONS (1) Division of Veterinary Services
(a) In Scientific Journals 1. Baker, Maureen K. & du Casse, F.W.W. 1968.
Tick infestation of livestock in Natal. II. The role played by goats as reservoirs of the economically important cattle ticks. J.S.Afr. Vet.Med.Ass. 39(3), 55-59.
2. Erasmus, J.A. & de Vry, J. 1968.
Levels of plasma glutamic transaminase in sheep from the Cape Midlands. J.S.Afr. Vet.Med.Ass. 39(3), 19-21.
3. Young, E. 1968
Management of adult wild ungulates. African Wild Life. 22, 217.
4. Young, E & Wagener, L.J.J. 1968.
The impala as a source of food and by-products. J.S. Afr. Vet.Med.Ass. 39(4), 81-86
5. Young, E & Oelofse, J. 1969
Management and nutrition of 20 newly captured young African elephants in the Kruger National Park. Int.Zoo.Yearbook. 9, 179.
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6. Young, E & Van den Heever, L.W. 1969
The African buffalo as a source of food and by-products. J.S. Afr.Vet.Med.Ass. 40(1), 83-88
7. Zumpt, I.F. 1968
The feeding habits of the yellow mongoose, Cynictis penicillate , the suricate, Suricata suricatta, and the Cape ground squirrel, Xerus inauris . J.S. Afr.Vet.Med.Ass. 39(4), 89-91
(b) In Departmental Publications 1. Van Heerden, A. 1968
Bovine Tuberculosis. Farming in South Africa. Aug. 1968.
2. Van Heerden, A. 1969
Sheep Scab. Farming in South Africa. April 1969.
(2) Veterinary Research Institute, Onderstepoort
In Scientific Journals 1. Barnard, B.J.H. 1968
Die diagnose van Vibriose by beeste. Jl.S.Afri.Vet.Med.Ass. 39(2), 75-78.
1. Barnard, B.J.H. 1968
Die diagnose van Vibriose by beeste. Jl.S.Afri.Vet.Med.Ass. 39(2), 75-78.
2. Bigalke, R.D., 1966.
Elephant skin disease of cattle – a bushveld problem. J1.S.Afri.biol.Soc., 7, 37-39.
3. Bigalke, R.D., 1968.
Theileriasis. Veterinary Encyclopedia 4, 2209-2218. Copenhagen: Medical Book Company.
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4. Bigalke, R.D., 1968.
Trypanosomiasis. Veterinary Encyclopedia, 4, 2300-2306. Copenhagen: Medical Book Company.
5. Bigalke, R.D., 1968.
New concepts on the epidemiological features of bovine besnoitiosis as determined by laboratory and field investigations. Onderstepoort J. vet. Res., 35, 3 – 138.
6. Brown, J.M.M., 1968.
The chemical pathology of ovine Icteric States. 3 Icterogenin induced cholestasis. J1. S. Afri. Vet. Med. Ass., 39(3) 35-48.
7. Brown, J.M.M., 1968.
Biochemical studies on geeldikkop and enzootic icterus. Onderstepoort, J. vet. Res., 35 319-576.
8. Els, H.J. & Verwoerd, D.W., 1969.
Morphology of blue tongue virus. Virology, 38
9. Gerneke, W.H., 1969.
Mamalian Epithelial tissue. Spectrum 7(1): 52-57.
10. Gerneke, W.H., 1968.
Current trends on the role of the Y-chromosome in mammalian intersexes. Proc. Of the 3rd Congress of the S.A. Genetic, Soc., 1-3.
11. Heinichen, I.G., 1969.
Karyotype of the Gemsbok and Springbok J1. S. Afri. Vet. Med. Ass., 40(1): 71-72.
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12. Heinichen, I.G. 1969.
Karyylogical Studies on Southern African Perissodactyla. J. S. Afri. Vet. Med. Ass., 40(1) 99-100.
13. Howell, C.J., 1968.
Die rol van sekere muggies (Diptera: Nematocera) op die gebied van Openbare Gesondheid. Inst. Openb. Ges. 1968. 105-111.
14. Howell, C.J. & Holmes, G.W., 1969.
The control of Simuliidae in the Vaalharts irrigation complex. J1. S. Afri. Vet. Med. Ass., 40(1) 59-67.
15. Lecatsas, G., 1969..
Anatomy and cell polarity in a plant tumour. S. Afri. J. Sci., 65: 55-59.
16. Lecatsas, G. & Weiss, K.E., 1968.
Electron Microscopic Studies on BHK 21 cells infected with Rift Valley Fever Virus. Archic. Ges. Virusforsch., 25, 58-64.
17. Lecatsas, G., 1969.
The structure of Bovine Ephemeral Fever Virus. J.S. Afr. vet. Med. Ass., 40.
18. Loveday, R.K., 1968.
Diarrhoea in pigs. Fmg. S. Afr., 44, 9-10.
19. MacKenzie, H.I. & Van Rensburg, I.B.J. 1968.
Ammelide and Ammeline as non-protein nitrogen supplement for sheep. J1. S. Afr. vet. Med. Ass., 39(2) 41-45.
20. Malherbe, W.D. 1968.
A clinico-pathological study of Babesia canis infection in dogs. D.V.Sc. Thesis, University of Pretoria.
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21. Malherbe, W.D. 1969. Blood parasites .
Textbook of Veterinary Clinical Pathology. Baltimore.
A note on an abnormal haemoglobin in cases of the Geeldikkop-enzootic icterus disease comple. J1. S. Afri. Vet. Med. Ass., 39: 89.
26. Nevill, E.M., 1968.
A significant new breeding site of Culicoides pallidipennis. Carter, Ingram and Macfie (Diptera: Ceratopogonidae) J1. S. Afri. Vet. Med. Ass., 39(3) 61.
Bracken poisoning in cattle in the Natal Midlands. J1. S. Afr. Vet. med. Ass. 39(3), 91-99.
38. Verwoerd, D.W., 1969.
Purification and characterization of bluetongue virus. Virology, 38.
15. LEGISLATION During the report year the Government Notices listed below were published under the Animal Diseases and Parasites Act (Act No. 13 of 1956). (a) Government Notice No. 1298 of 26 July 1968 to prevent the introduction,
occurrence or spread of Newcastle Disease by controlling the movements of poultry and poultry products in the magisterial district of Pretoria and a portion of the magisterial district of Brits.
(b) G.N. No. 490 of 2 August 1969 to set out the remuneration for professional
assistance rendered to the public by State Veterinarians, and to repeal G.N. Nos. 2573 of 27 November 1953 and 1165 of 15 August 1958.
(c) G.N. No. R1327 of 2 August 1968 to amend the Schedule to G.N. R1531 of
4 October 1963 and lay down a new scale of compensation payable for animals destroyed or slaughtered under the Animal Diseases and parasites Act.
(d) G.N. No. R1955 of 25 October 1968 to amend the Schedule to G.N. R1298 of
26 July 1968 and to extend the control of movements of poultry and poultry products to the magisterial districts of Pretoria and Brits and a portion of the magisterial district of Warmbaths.
(e) G.N. No. R2252 of 13 December 1968 to promulgate regulations in respect of
the compulsory vaccination of all heifers between the ges of 3 and 10 months the marking of such heifers, and the prohibition of vaccination of cattle over the age of 10 months.
(f) G.N. No. 790 of 14 May 1969 to promulgate the Animal Diseases and
Parasites Amendment Act (Act No. 51 of 1969). (g) G.N. No. R136 of 30 May 1969 to proclaim the coming into operation of Act 51
of 1969 on that date. (h) G.N. No. R947 of 13 June 1969 to further amend Part X of the regulations set
forth in the Schedule to G.N. R1531 of 4 October 1963, as amended by G.N. R55 of 17 January 1969.
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(i) G.N. No. R962 of 13 June 1969 to repeal the Newcastle Disease restrictions
laid down by G.N. No. 1298 of 26 July 1968 and amended by G.N. R1955 of 25 October 1968.
Under the Livestock Brands Act, 1962 (Act No. 87 of 1962), the following
Government Notices were published: (a) G.N. No. 206 of 21 February 1969 announced the appointment of specified
officers of the Division of Veterinary Services as Inspectors of Brands. (b) G.N. No. 207 of 21 February 1969 announced the appointment of Dr. M.C.
Lambrechts in the capacity as Chief of the Division of Veterinary Services as Registrar of Brands.
16. TECHNICAL RELATIONS WITH OTHER COUNTRIES (1) Liaison and Co-operation with African Territories One scientist from Botswana, one from Malawi and three from Rhodesia visited the Veterinary Research Institute and the Division during the year. Dr. K.E. Weiss visited Malawi on invitation, to advise this country on the planning and building of a central laboratory for veterinary research and diagnostic services. A number of specimens were received for examination and diagnosis, and advice was given in connection with diseases of stock in our neighbouring countries. Considerable quantities of vaccine, produced at the Institute, were sold to these countries. Under Trypanosomiasis details were given of the role played by South Africa in the interterritorial tsetse fly eradication campaigns. In connection with the necessary planning, Dr. E.B. Khuge held discussions during March 1969 with representatives of Angola and S.W.A. at Runtu in the latter territory. During the period April 28 – May 1 representatives of Angola, Botswana, Mocambique, Rhodesia, S.W.A. and the Republic met in Salisbury for discussions on tsetse fly control in Southern Africa. The Republic was represented by Drs. M.C. Lambrechts and E.B. Kluge. Dr. M de Lange represented the Institute and Dr. M.C. Lambrechts the Division at the annual meeting of the S.A.R.C.C.U.S. Standing Committee for Animal Health in Lourenco Marques during May 1969.
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(2) Liaison with Overseas Countries (a) Scientific Visitors
Ninety four scientists from 19 overseas countries visited the Institute for periods varying from one day to several months or years; in the latter case as guest workers in one or more of the different sections of the Institute. Four young veterinarians from South American countries on study grants, arrived during the year for post graduate study at the Institute. These grants were made by the South African Government through the Department of Foreign Affiars and the duration of study is for one year. Three students are from Brazil and one from Bolivia. (b) Technical Assistance and Advice
As World Reference Centre for Bluetongue and Horsesickness the Institute experienced a quiet period. No major outbreaks or spread of bluetongue or horsesickness outside of the recognised enzootic areas have been reported during the past year. Notwithstanding the fact that no specimens were received, the laboratories providing this service have been engaged in the preparation and testing of reference antigens and antisera to the established antigenic types of virus. Materials for diagnostic tests has been forwarded to Israel and Pakistan. (c) International Organisations
Dr. B.C. Jansen, Chief Director of Veterinary Services, and Dr. P.R. Mansvelt, Deputy Chief, Division of Veterinary Services attended the Annual Congress of the O.I.E. in Paris in May 1969. (d) Conference and Meetings
1. Drs. B.C. Jansen and P.R. Mansvelt – Annual Congress of O.I.E. in Paris, France, - 16-24.5.69.
2. Drs. M.C. Lambrechts and M. de Lange – Meeting of SARCCUS,
Committee on Animal Health, Mocambique, 4-10.5.69.
3. Prof. R.K. Reinecke – Seminar on the Biological Aspects of Bilharzia, Salisbury, Rhodesia, 8-16.4.69.
4. Dr. P.G. Howell – Meeting of O.I.E. Committee on Foot & Mouth
Disease, Paris, France, 24.11 – 6.12.68.
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5. Prof. H.P.A. de Boom – 66th Annual Congress of S.A. Association for
the Advancement of Science, Mocambique, 29.6 – 3.7.68.
6. Dr. D.W. Verwoerd – 1st International Congress on Virology, Helsinki, Finland, 13-21/7/68.
7. Dr. R.K. Loveday – World Veterinary Congress on Diseases of Pigs,
Cambridge, England, June 1969. (e) Study Tours and Official Visits
1. Dr. H.H. Kleeberg – South America. On invitation of the Minister of Agriculture, Peru, to lecture and advise on the control of Tuberculosis in cattle, 2-30.11.68.
2. Dr. P.G. Howell – Gaberones, Botswana. Research on Foot and Mouth
Disease, June 1969.
3. Dr. K.E. Weiss – Malawi. Advice on planning of diagnostic laboratory, 10-16.9.68.
4. Prof. H.P.A. de Boom – seconded to University of Mocambique to
organise the course in Anatomy, Faculty of Veterinary Science, November 1968 – July 1969.
5. Dr. B.J. Erasmus – Attended Second International Congress on Equine
Infectious Diseases, Paris, France. Thereafter a study tour to various institutes in Switzerland, Austria, Italy, Germany and England, 15.6 – 31.7.69.
6. Dr. B J. Barnard – Parkville, Australia. Study tour on bovine pleuro-
pneumonia and vibriosis. June – July 1969.
7. Mr. J.R. Malan – Rhodesia, investigation of dipping tests.
8. Dr. L.W. van den Heever – Bulawayo, Rhodesia. Examiner for final examinations for Certificate in Meat Inspection.
