88 ABSTRACTS.

TUBERCULOSIS OF THE DOG.

IN the preliminary portion of his monograph the author deals at some length with the literature regarding the occurrence of tuberculosis in the dog, particularly with regard to the frequency with which it is encountered, the investigations that have been made up to the present regarding the virulence of the strains of tubercle bacilli isolated from such cases, and the susceptibility of the dog towards tubercle bacilli derived from different sources.

As an introduction to the description of his own investigations the author gives a brief account of the general procedures adopted.

The eleven cases investigated by the author were collected during the period 1908-12, and in almost every case the dogs were obtained for examination after death had occurred.

Case I.-Fox terrier, one year old. Died of distemper. At the post-mortem examination purulent bronchitis and tuberculosis of

the mesenteric glands were found. Microscopic examination of the glands showed that the greater part of

the gland was necrotic, there remaining only a rim of normal gland tissue, which was separated from the necrotic portion by a layer of epithelioid tissue. Bacilli were present in enormous numbers in the cellular tissue. The majority of the bacilli were long :lnd slender and stained evenly throughout.

Cultures on solid glycerin-horse-serum and glycerin-potato were clearly visible by the twenty-fourth day. On potato the colonies presented a dry, granular appearance, and were of a yellowish-brown colour. On the surface of serum the growth took the form of a thick, wrinkled layer, which showed a tendency to extend up the sides of the tubes. Growth was very abundant on both media as well as upon glycerin-broth. With increasing age the cultures acquired a reddish-yellow tint.

Two guinea-pigs inoculated subcutaneously died with generalised tuber­culosis in 75 and 107 days respectively. The lesions showed little tendency to necrosis, and there was a considerable amount of new connective tissue formed.

Two rabbits inoculated subcutaneously were killed on the 338th day. They had appeared to be healthy during the whole of the period, and had increased in weight. The only lesions found at the post-mortem were abscesses about the size of chestnuts at the seat of inoculation, the contents of one being muco-purulent and of the other dry and crumbling. Cultures made from these lesions showed abundant growths in a month, and a guinea-pig inoculated from one of the lesions died in 191 days of generalised tuberculosis.

A calf which had passed the subcutaneous tuberculin test was inoculated subcutaneously with ISO milligrammes of culture. The animal was killed on the 283rd day. At the seat of inoculation there was an area of dense fibrous tissue about the size of a chestnut, but without any trace of caseation. The prescapular gland on the same side was not enlarged, and showed no macroscopic alteration. The left bronchial and posterior mediastinal glands showed a few caseo-calcareous tubercles varying in size up to a pea. The rest of the organs appeared to be normal.

ABSTRACTS. 89

Two guinea-pigs inoculated with material taken from the gland died with generalised tuberculosis in eighty-four and ninety-seven days respectively.

A goat which had passed the subcutaneous tuberculin test was inoculated intravenously with 50 milligrammes of a fifth subculture of the bacillus' isolated from the dog. The animal was killed nineteen months after inoculation. As some of the material had escaped into the subcutaneous tissue at the time of inoculation there was a caseous local lesion and involve­ment of the lymphatic glands in the neighbourhood. A few very small calcareous nodules were present in the lungs, and there were two caseo­purulent abscesses in the sternum. The mediastinal and mesenteric glands contained small calcareous centres. Tubercle bacilli could not be detected by the microscope in material taken from these lesions, but guinea-pigs inoculated from them died of generalised tuberculosis.

Two rabbits inoculated subcutaneously and intravenously were killed about four and a half months later, and were found to be free from tuberculous lesions.

Case lI.-" Doberman-Pinscher," nine months old. The post-mortem examination revealed the presence in the peritoneum of

a large quantity of turbid, greyish-red, purulent exudate, the parietal peri­toneum showing soft, grey granulations about the size of pins' heads. The omentum formed a large sausage-like mass lying along the greater curvature of the stomach, and composed of larger and smaller nodules, which on section were found to be caseous. The spleen was only slightly enlarged, but the dorsal portion was entirely caseous and adherent to the omentum. The spleen, omentum, pancreas, and mesentery formed a large single caseous mass. The mesenteric glands were enlarged and firm, and on section were found to be caseous. The mucous membrane of the stomach and intestines was normal, as were the kidneys and their associated glands. The liver, which was slightly enlarged, showed marked fatty de­generation, and the portal glands were enlarged but not visibly caseous. The inferior cervical glands were enlarged and for the most part caseous. Numerous tubercle bacilli were found in film prerarations from the diseased organs.

Microscopic examination of the liver showed that although the organ appeared to be normal to the naked eye there was in reality an aCllte miliary tuberculosis. The bacilli present in the lesions were for the most part long and slender, and did not stain evenly.

Culture media were inoculated, and the growths resulting presented a dry, granular appearance, the cultures having a yellowish-brown tint.

A fifteen-weeks-old calf was inoculated subcutaneously with 100 milli­grammes of culture, and was killed thirteen months later. At the seat of inoculation there was an area of thickened subcutaneous tissue measuring 3 cm. in diameter and 1- cm. in thickness, and containing in its substance only a few calcified granules. The adjacent lymphatic gland was not enlarged, and showed no evidence of disease. There were no macroscopic lesions in any of the internal organs.

A goat which had passed the tuberculin test was inoculated intravenously with 50 milligrammes of culture. Four months after inoculation the animal suddenly became ill, with rise of temperature, loss of appetite, and pro­nounced diarrhcea, accompanied by marked wasting. Twelve days later the goat died. At the seat of inoculation there was a caseous centre in the subcutaneous connective tissue as large as a pea. The jugular vein was partially thrombosed, and preparations from both these lesions showed large numbers of long, unevenly stained bacilli. The cause of death was severe

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gastro-enteritis, which was unconnected with the inoculation. No other lesiGms of tuberculosis could be found.

A rabbit inoculated subcutaneously with 10 milhgrammes of culture showed only a local caseous lesion containing tubercle bacilli.

A second rabbit inoculated intravenously with '1 milligramme of culture died on the sixty-first day. The lungs contained numerous irregular yellow nodules varying in size up to that of a hemp seed. Close inspection showed that each nodule had a caseous centre surrounded by a hyaline zone. Apart from the enlarged and partially caseous bronchial glands no other lesions of tuberculosis were found.

Guinea - pigs inoculated subcutaneously and intramuscularly died of generalised tuberculosis.

Case III.-Scotch sheep dog, four months old. The animal was destroyed by strychnine on account of meningitis.

Apart from small hremorrhages in the meninges of the brain the central nervous system appeared to be normal. In one of the mesenteric glands there was a single lesion as. large as a linseed containing thick greenish­yellow pus. This was found to contain long, slender, irregularly stained tubercle bacilli.

Cultures were obtained on glycerinised potato, the cultures presenting a dry, granular appearance. The bacillus grew rapidly upon glycerin-broth, forming a thick film.

A guinea-pig inoculated subcutaneously with material from the original lesion died from acute enteritis on the nineteenth day. At the seat of inoculation there was a large abscess, and young miliary tubercles were found in the internal organs. Further guinea-pigs inoculated with emulsion of the spleen of the first guinea-pig died of generalised tuberculosis.

A calf inoculated subcutaneously with ISO milligrammes of culture was killed eight months later. At the seat of inoculation there were two caseous centres as large as hazel nuts and a smaller one in the connective tissue. The prescapular gland was not enlarged, but on section appeared to contain more connective tissue than the corresponding gland on the opposite side. All the other organs appeared to be normal. Tubercle bacilli were found in very small numbers in the caseous centres, but there was no evidence of tuberculosis in the prescapular gland.

A goat inoculated intravenously with 50 milligrammes of culture was killed eight months after inoculation. The only lesions di~coverable were a few calcareous centres as large as pins' heads in the bronchial glands and under the pleura, one centre containing dry caseous material as large as a pea, .and a few smaller ones in the mesenteric glands. No tubercle bacilli could be discovered microscopically.

A guinea pig inoculated from the mesenteric lesion died of generalised tuberculosis.

Two rabbits inoculated subcutaneously and intravenously showed no lesions.

Guinea-pigs inoculated with culture died of generalised tuberculosis. Case IV,-" Boxer," two years old. Killed with strychnine. The following lesions were found: Pleurisy on the right side of the chest

with an abundant purulent exudate. The visceral pleura was thickened, and the parietal ph ura showed a number of small yellowish outgrowths. The main lobe of the right lung contained an abscess about the size of a bean. The thoracic glands appeared to be abnormally mOIst, but no centres were visible in them with the naked eye. One of the mesenteric glands contained an ~bscess as large as a pigeon's egg, with thin purulent contents. No other

ABSTRACTS.

lesions were observed. Tubercle bacilli were sparingly present in the lesions.

A guinea-pig inoculated subcutaneously from the lesion in the lung died of generalised tuberculosis on the sixty·fifth day. The virus was passed through several guinea-pigs before pure cultures were obtained.

Cultures were obtained upon potato and serum, but they were very meagre, and developed somewhat slowly. They grew either as scattered small colonies or a delicate film of growth which showed no tendency to become granular. A thin veil-like growth developed on the surface of glycerin-broth.

As the author was not certain whether his cultures were pure, a calf was inoculated subcutaneously with the emulsion obtained by grinding up about three-quarters of the spleen of a guinea·pig inoculated forty days previously with 10 cc. of salt solution, the emulsion being filtered through gauze before use. The emulsion was very poor in bacilli.

Three weeks after inoculation the anilllal was obviously ill, and was heard to cough for the first time. At the seat of inoculation there was a swelling measuring about 8 cm. in diameter by 3 cm. in thickness. The swelling was hot and painful. The prescapular gland was rather larger than a hen's egg.

Forty-five days after inoculation the calf was killed, as it appeared that death would soon take place naturally.

The local lesion, which involved the skin, subcutaneous tissue, and superficial layers of the muscles, contained caseous material, and the pre­scapular gland contained caseo-calcareous matter. Examination of the organs showed that there was generalised tuberculosis.

Rabbits and guinea-pigs inoculated intravenously and subcutaneously died of generalised tuberculosis.

Case v'-A five-years-old lap dog. The dog was admitted to the institute with the history that it belonged to

a person suffering from tuberculosis. The animal had always lived in very close contact with its owner. Symptoms suggestive of tuberculosis had made their appearance two years previously.

The animal was injected subcutaneously with 30 milligrammes of tuber­culin, and the following day was found dead.

At the post-mortem the lungs were found to contain several caseous centres of various sizes and several cavities as large as hazel nuts. These cavities contained thin pus-like material. Miliary tubercles were also dis­coverable in the lung tissue. The bronchial glands were slightly enlarged, but not obviously tuberculous. The rest of the thoracic and abdominal organs were normal in appearance. The caseous material contained large numbers of slender, unevenly stained tuhercle bacilli.

Microscopic examination revealed the presence of small tubercles in the bronchial and mesenteric glands.

A series of passages through guinea-pigs was made before the organism was obtained in pure culture. GUinea-pigs died of generalised tuberculosis, but rabbits showed only local lesions and recovered.

In artificial culture growth was very rapid, and on solid media took the form of wart-like colonies. On the surface of broth a thick, wrinkled film developed.

A calf inoculated with a pure culture subcutaneously showed a swelling at the seat of inoculation, which was not very painful, and slight enlargement of the prescapular gland. The animal was killed about five and a half months later. At the seat of inoculation there was a small fibrous thickening, which on section was found to be beset with minute calcareous points. The pre·

ABSTRACTS.

scapular gland on the same side was about twice the normal size and markedly diseased, there being extensive caseation and calcification. The lungs contained five tubercles about the size of peas, but the slightly enlarged bronchial glands did not show any evidence of disease. The peritoneal cavity contained about 300 cc. of turbid serous fluid, and, save for some small fibrous outgrowths on the omentum, the peritoneum appeared to be normal. The liver contained numerous small, rounded centres, and the kidneys appeared to be cirrhotic. Tubercle bacilli were found in the lesions, ncluding those of the omentum, but both microscopic examination and experimental inoculation failed to reveal their presence in the liver and kidneys. The lesions present in the liver were of the nature of a purulent inflammation of the bile ducts.

A goat inoculated intravenously with the same culture was killed six and a half months after inoculation. There was a caseous lesion as large as a pea over the jugular vein, and the prescapular gland, which was not enlarged, contained some small calcareous centres.

Two rabbits inoculated subcutaneously and intravenously were killed on the 180th day. There was an abscess as large as a hazel nut and containing mucoid pus at the seat of inoculation in the animal inoculated subcu­taneously, and in both rabbits the lungs contained a few tubercles as large as hemp seeds. On microscopic examination these tubercles were found to have calcareous centres surrounded by fibrous tissue. Tubercle bacilli were present in the nodules in fairly large numbers.

A guinea-pig inoculated subcutaneously died of generalised tuberculosis on the seventy-eighth day.

Case VI.-Fox-terrier, four years old. Killed on account of chronic bronchitis.

The bronchial glands formed a mass as large as a fist surrounding the bifurcation of the trachea and causing it to be compressed laterally. The lungs contained a large number of very small hyaline centres. The omentum was thickened and adherent to the pancreas and spleen. It contained a number of caseous nodules. The liver contained a number of tubercles varying from I mm. to 3 cm. in diameter. The larger ones were rather fibrous and more or less caseous, while the smaller ones were hyaline in appearance. The portal glands were somewhat enlarged and partly caseous. The left kidney contained three white tubercles as large as pins' heads. No tubercle bacilli could be found in film preparations made from the diseased organs, but they were found in small numbers in sections.

A guinea-pig which was inoculated subcutaneously with material obtained from the portal glands died from an accidental infection. The case was not investigated further.

Case VII.-Badger-hound, about six months old. Killed on account of ascites.

The animal was in poor condition. The peritoneal cavity contained several lit res of clear serous fluid, and the peritoneal membrane showed no evidence of inflammation. The omentum contained nodules which on section were found to be of a yellow colour and caseous in the centre. The spleen was firm in consistence, and the follicles were very distinct. The splenic glands were somewhat enlarged, but not caseous. The mesenteric glands were enlarged and caseous. The liver was somewhat larger than normal, and was beset with very small, round, hyaline centres. The portal glands were enlarged and caseous at places. The anterior mediastinal glands were enlarged and showed some caseous centres. Numerous tubercle bacilli were found in preparations from the various diseased organs.

ABSTRACTS, 93

Microscopic examination of the spleen revealed the presence of small tubercles.

Cultures were obtained, and these grew very rapidly, forming large, fiat colonies on the surface of solid media. On the surface of liquid media a thin film developed. In subcultures growth was very rapid, and a thick wrinkled film developed upon the surface of broth.

Guinea-pigs inoculated with material obtained from the liver and omentum showed generalised tuberculosis.

A calf inoculated with pure culture subcutaneously showed at the post­mortem nine months later a small fibrous thickening at the seat of inoculation, and slight enlargement of the prescapular gland on the same side, but no other lesions.

A goat inoculated intravenously with 20 milligrammes of culture died on the twenty-ninth day. The lungs contained innumerable miliary tubercles, and the bronchial and mediastinal glands were enlarged and caseous. The spleen was enlarged and rather firmer in consistence than normal. All the other organs appeared to be normal.

Microscopic examination of the spleen revealed the presence of miliary tubercles.

Rabbits inoculated subcutaneously showed only a local lesion, while two rabbits inoculated intravenously were found to be free from lesions when killed five and seven months later.

A guinea-pin inoculated subcutaneously with 5 milligrammes of bacilli was killed on the forty-fifth day and found to have generalised tuberculosis.

Case VIII.-Scotchdeerhound, one year old. The dog was destroyed on account of paralysis of the hind legs following distemper.

The whole of the organs appeared to be normal, save for a mesenteric gland which was enlarged and contained some dry, firm, caseous material. Numerous tubercle bacilli were discovered in preparations from this caseous substance.

Cultivation from the caseous mesenteric gland absolutely failed. A guinea-pig inoculated subcutaneously showed enlargement of the

nearest lymphatic gland, which appeared to be cirrhotic, and the spleen, which was normal in size, contained a few tubercles as large as hemp seeds. Tubercle bacilli were found by microscopic examination of the lymphatic gland, but not in the splemc lesions. The case was not investigated further.

Case IX.-German pointer, three years old. On post-mortem examinatIOn the following lesions were found: The chest cavity contained a large quantity of purulent exudate mixed with blood. The visceral and parietal layers of the pleura were covered with fiat, soft granulations of a yellowish colour. The lungs were collapsed as a result of the pressure exerted by the exudate, and in the posterior portion of the right lung there was a large pneumonic area, which on section was found to be composed of a number of softened caseous areas. There were also some cavities in the lung tissue. The rest of the lung tissue contained a number of firm greyish nodules about the size of peas. The anterior mediastinal glands were greatly enlarged, but contained no obvious lesions. The bronchia! and posterior mediastinal glands were only slightly enlarged, and presented a moist appearance on section. The mesenteric glands were greatly enlarged and contained softened and partly calcified centres. Tubercle bacilli were found in all the diseased organs, and were especially numerous in the necrotic areas in the lungs and in the material present in the bronchi.

The author was unable to obtain pure cultures of the bacillus, and experi-mental animals died of mixed infections. '

94 ABSTRACTS.

Brief details are given of two guinea-pigs inoculated subcutaneously with material taken from the diseased organs. In each of these generalised tuberculosis developed.

A rabbit inoculated subcutaneously from the spleen of one of these guinea-pigs died on the sixty-seventh day. There were miliary tubercles in the lungs, a large caseous ulcer at the seat of inoculation, and enlargement and caseation of the lumbar lymphatic glands. The liver, spleen and kidneys appeared to be normal. Numerous short tubercle bacilli were present in the diseased tissues.

Case X.-Rough-haired terrier, seven years old. The animal had been under treatment for coughing and wasting.

The following lesions were found at the post-mortem: The chest cavity contained a small quantity of clear serous exudate, and the parietal and visceral layers of the pleura were covered with small flat outgrowths of a yellow colour. Beneath the pleura the lung tissue contained a small number of hyaline nodules as large as pins' heads. The bronchial and mediastinal gla:1ds were markedly enlarged, and on section presented a yellowish-white appearance, but there was no caseation. The liver contained a large number of small, round, discrete nodules measuring about 1 mm. in diameter. The larger ones showed central caseation. The portal glands were firm and enlarged, but were not visibly caseous. The omentum, spleen, stomach and intestine and the associated glands appeared to be normal. Long, slender tubercle bacilli were found in the liver lesions.

Two guinea-pigs inoculated from the diseased organs died of generalised tuberculosis, and a rabbit inoculated from one of these when killed after an interval of seven months showed no lesions of tuberculosis.

After several passages through guinea-pigs the author was able to obtain pure cultures.

Upon the surface of serum primary cultures showed a delicate granular layer, the granules increasing in size and eventually developing. into flat scale-like colonies. Growth took place rapidly upon potato, and a thick warty layer was formed.

A tubercle-free calf inoculated sutcutaneously with 60 milligrammes of culture was killed five months after inoculation. At the seat of inoculation there was a fibrous thickening in the subcutaneous tissue about the size of a hazel nut. On section this was found to contain a quantity of thin pus. The wall of the abscess cavity was calcified. The prescapular gland on the same side was not enlarged, but a calcified centre about the size of a hemp seed was found beneath the capsule. Tubercle bacilli were present in small numbers in the pus from the local lesion.

A tubercle-free goat was inoculated intravenously with the same culture as that used for the calf, the dose administered being 40 milligrammes. The animal was killed four months later and the only lesion discovered was an abscess about the size of a hazel nut at the seat of inoculation. Tubercle bacilli ,were found in small numbers in the pus.

A rabbit inoculated intravenously with '1 milligrammes of culture showed only three caseous centres in the lungs measuring less than 2 mm. in diameter when killed on thel22nd day.

A second rabbit inoculated subcutaneously with 10 milligrammes of culture showed an abscess as large as a hazel nut at the seat of inoculation only.

A guinea-pig inoculated subcutaneously with 5 milligrammes of culture died on the I22nd day of generalised tuberculosis.

Case XI.-A three-years-old draught dog. Killed on account of chronic unilateral pleurisy.

ABSTRACTS. 95

' The left pleural cavity contained about 7 litres of clear serou~ fluid, and the right cavity about 100 cc. only. The parietal and visceral pleura on the left side were covered with a large number of cauliflower-like outgrowths of a yellow colour_ The left lung was entirely collapsed owing to the pressure of the exudate. The lungs and the bronchial glands appeared to be normal. The anterior mediastinal glands were somewhat enlarged and were rather firm in consistence. Tubercle bacilli could not be found in preparations made from the pleural outgrowths, but guinea-pigs inoculated from them died of generalised tuberculosis.

Pure cultures were obtained after the bacillus had been passed through a number of guinea-pigs. Tubes of solidified serum after about six weeks showed a continuous layer of growth in the form of a delicate, greyish pellicle, which at places developed flattened thickenings. Microscopic examination show«d that the majority of the baCilli were somewhat short. Some were thickened at their ends and others somewhat pointed. Growth upon potato was very slow.

A calf inoculated subcutaneously with 50 milligrammes of culture died on the thirty-fifth day. At the seat of inoculation there was an abscess as large as a potato filled with soft caseous material. The prescapular gland on the same side was as large as a hen's egg, and for the most part caseous. The lungs were beset with miliary tubercles, The whole of the lyml'hatic glands of the chest were enlarged and caseous. The liver, spleen, and kidneys contained miliary tubercles. Pt:yer's patches showed little necrotic areas, but the mesenteric glands were not visibly diseased_ The body lymphatic glands were enlarged but not visibly caseous.

A goat was inoculated intravenously with 35 milligrammes of culture, but during the operation the animal struggled and a portion of the liquid escaped into the connective tissue. Death took place on the thirty-first day. At the seat of inoculation there was an abscess the size of a walnut containing soft caseous material. The intima of the jugular vein showed some very small caseous nodules. The prescapular gland was enlarged and partly caseous. The lungs contained immense numbers of miliary tubercles: The thoracic lymphatic glands were enlarged and partly caseous. The liver and kidneys contained a few tubercles, while the spleen was enlarged and contained a great many. Numerous tubercle bacilii were present in the lesions.

Guinea-pigs and rabbits inoculated suhcutaneously and intravenously died of generalised tuberculosis, the lesions in the rabbits being very rich in tubercle bacilli.

The author gives a table showing the frequency of the occurrence of tuberculous lesions encountered in his series of cases. Tuberculosis of the mesenteric glands occurred in seven cases, of the lungs and of the bronchial glands in five, of the pleura and of the liver in four, of the mediastinal glands and of the omentum in three, of the spleen in two, and of the parietal peritoneum, mesentery, pancreas and kidneys in one each. Generalised chronic tuberculosis occurred in three instances, and acute miliary tuber­culosis in one.

The author points out the distribution of the lesions in the dog differs from that found in other animals, with the exception of the cat.

Tuberculous mesenteric glands were in the majority of cases only slightly enlarged, and the caseous material was generally very soft. No cases were observed in which tubercles were disseminated through the lungs as is setn in other animals. The condition is more usually a diffuse caseous pneumonia, associated with bronchitis, bronchiectases, and the formation of vomica!. The bronchial and mediasti~al glands often appeared to be normal to the

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naked eye, but were proved to contain tubercle bacilli. In the c.ase of chronic tuberculous pleurisy there was as a rule a large amount of exudate.

With regard to the histology of the lesions the author makes the following observations: "The tuberculous nature of the lesions was in the majority of cases difficult to determine from the examination of their histology. No typical tubercles were found. In some instances the tubercles consisted of a necrotic centre surrounded by more or less distinct epithelioid cells and lymphocytes, but more frequently the fibroblasts were spindle-shaped, and often there was no central necrosis. The diffuse inflammation of the lungs gave the appearance of a chronic pneumonia associated with necrosis. The pleural outgrowths were composed of granulation tissue which was rich in proliferating fibroblasts, budding capillaries, and lymphocytes. No giant cells were found in any section. In one case only was there any calcification, and then it was only slight in amount. In some cases, and especially in chronic tuberculosis of the liver and lymphatic glands, the lesions closely resembled fibro-sarcomata."

The results of inoculation of the various tubercle bacilli isolated from the cases are given in tabular form, and from tbese results the author concludes that in Cases IV. and XI. the bacillus belonged without doubt to the bovine type, while that isolated from Cases 1., II., III. and X. belonged to the human type. In three instances no cultures were obtained, and in two other cases a definite decision regarding the type of bacillus could not be arrived at. (Schornagel, Inaugural Dissertation, Utrecht, Beijers, 1914.)

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