1
Prevalence of vector borne diseases in a population of Sri Lankan
dogs
Abstract
Background: This study investigated the occurrence of canine TBDs in a set population of dogs in the
region of Colombo, Sri Lanka using a combination of Snap tests and blood smear examination. There are no
published reports on the presence of canine TBDs, Dirofilaria, Borrelia, Anaplasma, Ehrlichia, Hepatazoon,
and Babesia in Sri Lanka.
Methods: Samples of blood were collected into EDTA from a peripheral vein of 80 dogs in Colombo, Sri
Lanka. Snap tests were used to test for D.immitis, B. burgdorferi, E. canis/E. ewingii, A. phagocytophilum/A.
platys. Blood smears were also prepared from each sample, fixed and stained with a Wright-Gimesa stain
and analysed by microscopy.
Results: On microscopic evaluation of blood smears Hepatazoon gamonts were observed in 7 dogs (8.75%),
while Dirofilaria species were found in 4 dogs (5%). Snap tests indicate a total of 34 dogs (42.5%) were
positive. Ehrlichia was the most common with 29 dogs (36.25%) positive, followed by Anaplasma with 22
dogs (27.5%) positive, co-infection with both of these was also high with 19 dogs (23.7%) positive for both.
Potential tick vectors were found on 32 dogs (40%).
Conclusions: At least 4 canine TBDs were found to exist in the dog population in Sri Lanka. Ehrlichia was
found to be the most common pathogen. Co-infection of canine TBDs is also observed in Sri Lankan dogs.
2
Abbreviations
EDTA - Ethylenediaminetetraacetic acidCanine TBDs – Canine TBDs A. platys – Anaplasma platys
A. phagocytophilum - Anaplasma phagocytophilum
R. sanguineus - Rhipicephalus sanguineus
E. canis – Ehrlichia canis
E. chaffeensis – Ehrlichia chaffeensis
E. ewingii – Ehrlichia ewingii
E. ruminantium – Ehrlichia ruminantium
D. immitis - Dirofilaria immitis
D. repens - Dirofilaria repens
B. ceylonensis - Brugia ceylonensis
B. malayi- Brugia malayi
B. canis - Babesia canis
B. gibsoni - Babesia gibsoni
H. canis - Hepatazoon canis
H. americium - Hepatazoon americium
B. burgdorferi - Borrelia burgdorferi.
BPT – Blue Paw Trust
PCR – Polymerase chain reaction
HME - human monocytic ehrlichiosis
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1.0 Introduction
Vector-borne diseases account for 17% of the estimated global burden of infectious diseases in dogs [1].
There are many studies on vector-borne parasites infecting dogs around the world, [2,3,4,5] however, there
has been little data collected on the prevalence of these parasites on dog populations in Sri Lanka.
The dog population within Colombo, Sri Lanka is about 20,000. Within Sri Lanka approximately 3 million
dogs are free-roaming, however these numbers are changing due to sterilization clinics and rabies
vaccination projects.
Due to this high number of roaming dogs there is a persistent interaction between vaccinated and non-
vaccinated dogs, aiding disease transmission throughout the population. Totton et al, 2011 observed that
stray dogs are more likely to carry disease, exhibit poor body condition and malnourishment and be subject
to increased stress. These factors may cause them to be immunosuppressed and therefore more likely to
contract these communicable diseases [6].
1.1 Ticks:
Ticks are important vectors of disease in dogs and humans, as many of the diseases they carry are zoonotic
[2]. Ticks are well adapted to transmit a variety of organisms including viruses, bacteria and protozoa [7].
The prevalence of ticks in Sri Lanka is due to several factors such as availability of host species and humid
climate [8]
Ticks are obligate blood-feeding ecto-parasites (figure 1) that attach to hosts for a substantial amount of
time, allowing sufficient opportunity for disease transmission [8,9]. A total of 22 different tick species were
found in Sri Lanka [8], 21 of these were from wild animals. Rhipicephalus sanguineus was the most
common species in wild animals, this is significant as R. sanguineus is a carrier of 4 canine TBDs [10,11].
Ehrlichiosis, Anaplasmosis, Borreliosis, Dirofilariosis, Babesiosis and Hepatazoon are canine TBDs
considered endemic in warm climate zones [12]. The prevalence of these diseases were examined.
4
One of the predominant reasons for analysing these diseases was due to the zoonotic potential of all but
Hepatazoon. Our aim was to investigate the prevalence of these diseases in order to assess the zoonotic risk.
1.2 Ehrlichia
A gram-negative, obligate, intracellular bacterium from the family Anaplasmataceae [13,14,15,16]. There are
4 different Ehrlichia species; E. canis (worldwide) and E. chaffeensis (USA) E. ewingii (USA) and E.
ruminantium (Africa) [11]. E. canis is the most common species followed by E. ewingii. It is spread by tick
vectors, primarily Rhipicephalus sanguineus (brown dog tick) which is very common in Sri Lanka [8] also
Dermacentor variabilis transmits E.canis and Amblyomma americanum transmits E. ewingii [11]. The
bacterium predominately affects monocytes, macrophages and lymphocytes, with neutrophils and
eosinophils occasionally affected. In dogs there are several clinical signs associated with infection such as
fever, lethargy, anorexia, and lymphadenopathy.
E. canis causes canine monocytic ehrilichiosis [11,17]. Diagnosis of Ehrilichiosis is not usually made until
signs of weight loss, uveitis and haemorrhagic disorders become apparent [13]. Ehrilichiosis can cause
severe disease in humans as E. canis is closely related to Ehrlichia chaffeensis which causes human
monocytic ehrlichiosis (HME). This disease is characterised by fever, anorexia, vomiting, and weight loss
[10,18,19,20]. It has been suggested that climate change is contributing to increased geographical
distribution of R. sanguineus to areas previously uninhabited by ticks, thus spreading disease [8]. Ehrlichia
Figure 1 – Tick on the ear of a stray dog brought to the BPT for neutering
5
has been isolated from infected dogs in many countries including Spain, Greece, Egypt, Japan, Africa and
India [20,21,12].
1.3 Anaplasma
Canine anaplasmosis is caused by an intracellular rickettesial organism, two species are considered
pathogenic in dogs; Anaplasma platys and Anaplasma phagocytophilum [14,15]. The latter is considered
more pathogenic and zoonotic with the risk of causing granulocytic anaplasmosis. A. platys is only reported
to cause clinical infection when the animal is co-infected [12]. A. phagocytophilum is spread by Ixodes tick
and infects neutrophils and eosinophils causing fever, anorexia, lethargy. A. platys is spread by R.
sanguineus and mainly infects platelets causing cyclic thrombocytopenia [11,14]. Anaplasma and Ehrlichia
are common in tropical areas and are commonly seen as co-infections [13].
1.4 Borrelia
Borreliosis is caused by spirochaete bacteria transmitted by Ixodes tick [14]. Wormser (2006) reports more
common occurance in the northern hemisphere [22,15]. Borrelia burgdoferi sensu lato is the agent of human
Lyme disease, a severe disease in humans [22,25]. Many of the cases in dogs are seropositive and show no
clinical signs of the disease, although when clinical signs do present they most commonly cause disease in
the nervous system or in joints [10].
1.5 Dirofilaria
Dirofilaria immitis, Dirofilaria repens and Acanthocheilonema spp. cause heartworm disease in dogs, these
have all been reported in India [23]. It is currently thought that D. immitis is confined to northern India,
while D. repens to southern India. In Sri Lanka mosquitoes are very prevalent, this is important as filarial
nematodes tend to be common where mosquitoes are present [15]. Dirofilaria spp. is thought to affect the
lungs and lymphatic system of the animal. [7] It has been reported that the filarial species Brugia ceylonensis
is endemic in Sri Lanka, however is difficult to differentiate from B. malayi [23]. There have been reports of
human cases of dirofilariasis caused by Dirofilaria repens in Sri Lanka [24].
6
1.6 Babesia
Babesiosis is caused by an intraerythrocytic prioplasm protozoa from the phylum Apicomplexa [14,15,25]
there are two main species; Babesia canis and Babesia gibsoni [26,17]. Clinical signs include anaemia,
anorexia, pale mucous membranes, vomiting, and jaundice [25]. Disease is transmissible by Ixodid ticks,
primarliy Ixodes scapularis [26,27]. Babesia has zoonotic potential, the two agents causing human
babesiosis are Babesia microti and Babesia divergens, [28] thus confirming diagnosis in dogs has
importance in human health. There is currently no conclusive data on Babesia prevalence in India; the
reported prevalence in dogs ranges between 0.1-22% [26].
1.7 Hepatazoon
Hepatazoon canis and Hepatazoon americium causes canine hepatazoonosis an arthropod-borne infection
[14]. It is suggested to have been present among dogs in India since 1905 [30,31]. H. canis is worldwide and
generally subclinical with dogs appearing healthy; however H. americanum is more confined to the US and
causes severe disease. Rhipicephalus sanguineus is the main tick vector of H.canis. [32]. Hepatazoon is
transmitted differently than other tick-borne parasites; an infected tick must be ingested to cause infection
[10].
1.8 Aims:
The main aim of this study was to evaluate the burden of blood-borne parasites, many of which have
zoonotic potential, in a population of dogs presented to a neutering clinic in Colombo, Sri Lanka, in order to
gain further insight into the prevalence and impact of the above diseases in Sri Lanka.
1.9 Null hypothesis:
i) No difference between neutered or entire dogs positive for tick-borne diseases.
ii) No difference between owned or stray dogs positive for tick-borne diseases.
iii) No difference between sexes of dogs positive for tick-borne diseases.
7
2.0 Data collection:
The data for the project was collected from a set population of dogs in Colombo, Sri Lanka. Data was
collected in conjunction with the Blue Paws Trust (BPT), a sterilisation clinic, and neighbouring Pet Vet
Clinic. Colombo was the sole location studied, however the hope was that results collected are transferrable
to the rest of Colombo and possibly Sri Lanka. Dogs sampled were both pet dogs and stray dogs, varying
between completely stray and owned but roaming dogs.
A minimum size of 100 was aimed for, however it was only possible to attain 80 samples in the 2 week
period in October 2014.
The sampled stray dogs were caught and restrained by trained BPT staff with minimum force and stress. The
dogs were clinically assessed by vets at the BPT. The dogs were anaesthetised for surgery before any
sampling was performed; further reducing stress. This project has been approved by the Royal Veterinary
College Ethics and Welfare Committee.
Data recorded:
• Sex of each animal (male, female)
• Neuter status (Neutered, entire)
• Other illnesses – externally identifiable in stray animals as the history will be unknown; clinical
history was consulted for pets.
• Stray or owned (pet-non roaming)
• Breed
2.1 Sampling method:
Blood was collected using a 2.5ml syringe and 21gauge needle from a peripheral vein, either cephalic or
saphenous. Blood was immediately transferred into an EDTA tube and mixed to prevent clotting. Blood
smears were prepared and an IDEXX 4Dx Plus snap test was used.
The blood smear was made as described below see 2.3 method for creating blood smear.
8
IDEXX labs provided 100 4Dx Plus snap tests, these were used to test for Dirofilaria immitis antigen,
antibodys to Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis, Ehrlichia ewingii and
Borrelia burgdorferi.
2.2 The method of the snap test:
The snap test was used in accordance to the manufacturer’s instructions. (See appendix)
2.3 Method for creating blood smears
Capillary tubes were used to pull blood from the EDTA tube, a small drop of blood was placed from the
capillary tube onto the microscope slide. Another slide was then used to thinly spread the blood sample into
a bullet shape with a feathered edge. The viscosity of the blood affected the angle of the slide used to spread
the sample; a greater angle was used to spread blood of low viscosity and vice versa. This allows a
consistency in size and length of the blood smears. Blood smears were then air dried and dipped 10 times
into 100% alcohol to fix the slide and organisms. They were then air dried again and placed in the slide box
for transportation. They were stained with a Wright-Gimesa stain which allowed visualisation of bacteria/
parasites in the smear. The blood smears were examined under the microscope using X20, X40, and X100
(oil emersion) lenses.
2.4 Statistical method
SPSS Software version 22 was used to analyse the data. As the results were not normally distributed a
non-parametric test (Chi squared or χ2 test) was used to determine if results were statistically
significant (p<0.05).Fishers exact test may be given due to the small sample size. The population was
9
described using descriptive statistics and examined graphically. Two categorical sets of data were
compared; comparing sex, neuter status and ownership against positive test results.
3.0 Results:
Blood samples were taken from 80 dogs, 40 were from stray dogs at the BPT and 40 were pets from
the Pet Vet Clinic. Canine TBDs were diagnosed in 34 of the 80 dogs sampled; this represents 42.5%
of the population sampled.
3.1 Sex vs snap test result
Graph 1 shows more females were positive on the snap tests than males at 45.5% and 28.5% respectively.
Graph 1 – A bar graph to show the relationship between the sex of the dogs tested and the results of the snap tests.
10
!
There are more negative results in males (71.5%) than females (54.5%). However, statistical analysis
showed no correlation between sex and presence of infection; as determined by a Fishers exact test 0.373,
(p>0.05).
3.2 Diseases and Snap test results:
Number of positive and negative females and
males on the snap tests
Nu
mb
er
of
do
gs
0
13
25
38
50
Sex
Female Male
10
36
4
30
PositiveNegative
Graph 2- A bar graph to show numbers of dogs sampled which were found to be positive for canine tick borne diseases and predominantly which ones by the snap tests.
11
!
Anaplasma and Ehrlichia were the most commonly detected parasites in the tested dog population, see graph
2. Of the population 27.5% (n=22/80) tested positive for Anaplasma and 36.25% (n=29/80) positive for
Ehrlichia. Dirofilaria was uncommon with 1.25% affected (n=1/80). No Borelliosis was detected. Co-
infection with Anaplasma and Ehrlichia was relatively frequent with 23.7% (n=19/80) of dogs testing
positive for both.
Statistical analysis shows an association between positive snap test and Anaplasma (p=0.000), this was
consistant with Ehrlichia.
3.3 Presence of ticks vs snap test result
Results for the snap tests1
N
um
ber
of
do
gs
0
25
50
75
100
Parasites
D. immitis B.borgdoferi A. platys and E.canis
6151
100
58
99
19290221
PositiveNegative
Graph 3 – A graph to compare the number of dogs infected with ticks and infected with canine tick borne diseases
1IDEXX Snap 4Dx Tests
12
!
The majority of dogs did not have ticks detected on clinical exam 60% (n=48/80). Parasites were detected on
snap test in 50% of the population (see Graph 3), whether positive or negative for ticks. Ticks were found on
37.5% (n=30/80) of dogs where no parasitic infection was detected. Statistical analysis revealed no
correlation between the presence of ticks and a positive snap test for any disease tested; Fisher’s exact result
0.356.
3.5 Neuter status vs snap test result
A graph comparing percentages of animals with
ticks and parasites
Nu
mb
er
of
do
gs
0
25
50
75
100
Presence of ticks
Positive Negative
50
304040
48
32
TotalPositive parasites Negative Parasites
13
!
Graph 4 demonstrates no relationship between neutered dogs and positive snap tests as equal numbers of
neutered 42.8% (n=9/21) and entire 42.4% (n=25/59) dogs were positive, Fishers exact test 1.000, p>0.05.
3.6 Ownership status vs snap test result
!
Graph 5 illustrates a significantly higher proportion of stray dogs were positive when compared with pet
dogs 57.5% (n=23/40), Fishers exact test 0.012, p<0.05.
3.7 Neuter status vs Ehrlichia and Anaplasma
Negative Positive
Positive snap test
Negative Positive
Positive snap test
Graph 4 – A graph to show the relationship between neuter status (neutered or entire dogs) and their snap test results
Graph 5 – A graph to show the relationship between ownership (stray or pet) and snap test results
Graph 6 and 7 – Bar graphs to show the relationship between neuter status (neutered or entire) and presence of Ehrlichia spp. and
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Statistical analysis revealed no association between Ehrlichia and Anaplasma and neuter status. Of the entire
population studied, 36.25% (n=29/80) were positive for E. canis, whereas only 28.6% (n=6/21) of neutered
animals were positive for E. canis (see graphs 6 and 7). Fishers exact test 0.440, (p>0.05). This was the
same for Anaplasma 28.6% (n=6/21) of neutered animals were positive, fishers exact value of 1.000,
(p>0.05).
3.8 Blood smear pathogens
Blood smear results
Perc
en
tag
e
0
20
40
60
80
Pathogens present
D. immitis H. canis
7673
47
PositiveNegative
Graph 8 – a bar graph to show the presence of canine tick borne diseases on blood smears created from sample dogs.
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Blood smear examinations were negative for Ehrlichia, Anaplasma and Babesia, however graph 8 shows
Hepatazoon gamonts and Dirofilaria were observed with 5% (n=4/80) and 8.75% (n=7/80) positive
respectively.
4.0 Discussion:
4.1 Presence of disease:
Ehrlichia and Anaplasma
The main aim of this study was to determine the prevalence of canine TBDs in a sample population of dogs
in Sri Lanka. It was determined that the most prevalent disease was Ehrlichiosis (36.25%) followed by
Anaplasmosis (27.5%) and co-infection with both pathogens (23.7%). The result of this study are similar to
that conducted in India by Abd rani et al, 2011 which found H. canis, E. canis and A. platys most common;
with H. canis most prevalent [12]. Transmission of these diseases may be attributed to R. sanguineus, which
is the predominant carrier. R. sanguineus was reported in several studies to be one of the most common ticks
in Sri Lanka and the most abundant tick affecting both dogs and wild animals [8,12]. Interestingly,
Liyanaarachchi et al, 2015 also found Dermacentor auratus, which is thought to transmit Anaplasma platys,
to be the second least abundant tick species in Sri Lanka [8]. These findings are important as it provides
evidence of the presence of canine TBDs in Sri Lanka should lead to further research in this area.
Dirofilaria
We found one positive snap test for Dirofilaria, however microfilaria were found on seven blood smears.
The snap test only detects D.immitis antibodies therefore infection of other Dirofilaria species would not be
detected. The results are surprising as there is a 95% CL for both sensitivity and specificity on the test for
Dirofilaria, therefore it is likely the species found on the blood smear was Acanthocheilonema reconditum or
D. repens, the most common filarial parasite in Sri Lanka. Dissanaike et al, 1997 reported 30-60% of Sri
Lankan dogs are infected with D. repens [24]. Dirofilaria is also thought to be common in Sri Lanka due to
mosquito vectors which are ever present in the country.
Hepatazoon
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Hepatazoon gamonts were observed on seven blood smears. Its presence in the population can be expected
due to the abundance of R. sanguineus ticks. This finding supports studies which found Hepatazoonosis in
domestic dogs in Sri Lanka [32]. Although Hepatazoonosis causes disease in dogs it is not zoonotic
therefore implications to the BPT are minimal.
Babesia
Although Babesia has been reported to exist in India and worldwide no Babesia spp. were identified in this
study. [26,33]. This lack of evidence could be due to the small sample size and the location constriction, it
has also been suggested that multiple blood smears may need to be examined over several days to identify
the parasites [28]. Identifying Babesia on blood smears is an insensitive diagnostic method. Future research
could look into the use of PCR techniques, serology or cytology to improve sensitivity. [10].
Borrelia
The negative results for Borrelia were a very important finding as this is a serious zoonotic disease. To
improve the reliability of these results a bigger size sample and more locations in Sri Lanka should be
covered. This is of relevance because the ticks that transmit this disease, Ixodes species, are present in Sri
Lanka and reported to infect humans, not wild or domesticated animals [8].
The overall results of this study have few implications for the neuter project itself. However, it must be taken
into account that the pathogens isolated from the dogs included Ehrlichia, Anaplasma and Dirofilaria, all
have zoonotic potential. This means that the workers at the neuter clinic need to be cautious when examining
infected dogs.
4.2 Co-infection
This study supports Abd Rani et al, 2011 in displaying co-infection with canine TBDs is common [12,10].
This could be explained in Sri Lanka due to the main tick species R. sanguineus’ ability to simultaneously
harbour many of these diseases. It is reported to carry Babesia canis, Hepatazoon canis, Ehrlichia canis and
Anaplasma platys [10,11]. A consequence of this is one tick can transmit multiple canine TBDs to one host
weakening the immune system allowing for infection of other pathogens. R. sanguineus is more common in
17
urban areas [12,34], as this study was conducted in Colombo, the capital, it is presumed this is the main tick
affecting dogs tested. Co-infection is an important factor affecting treatment of these diseases [12], therefore
these results could provide reason behind potential treatment failures and shape future treatment plans.
4.3 Ticks
Of the sample population 40% (n=32) were found to carry ticks. A study conducted in Jodhpur, India into
health status of 323 sexually intact stray dogs found a 68% prevalence of ticks [6] indicating higher
prevalence in India. Although there are studies in Sri Lanka on the species of ticks present, there is limited
data on the overall prevalence of ticks on dogs, this is an area for future research.
This study showed no statistically significant relationship between the presence of canine TBDs and the
presence of ticks, this was surprising as correlations were found between these factors in India [12]. This
result indicates other factors may influence infection levels, such as species of tick and tick disease carrier
status. Our results may be affected by small sample size and limited data analysis methods. This study could
be improved by investigating which tick species were found on dogs studied, similar to a study done by
Liyanaarachchi et al, 2015 [8]. This would provide information on which diseases could be infective to BPT
workers and help with tick control/disease prevention. This was not feasible within this project but could be
an area for further study.
4.4 Neuter status vs snap test results
It was hypothesised that more neutered animals would be positive for tick-borne diseases than entire
animals.
No statistically significant relationship was found between neutered dogs and positive canine TBDs results,
p>0.05, supporting the null hypothesis. It is has been put forward by some studies that the sex hormones
play a vital role in the immune system response [35] therefore neutering, and the removal of these, could
cause a decreased immune response subsequently increasing infection risk. However, Kirkpatrick, 1988
demonstrated that gonadectomy decreases the likelihood of parasitism, therefore neutering is not considered
a predilection factor [36]. Abd rani et al, 2011 found neutered dogs were less likely to be PCR positive for
canine TBDs than entire dogs [12].
18
4.5 Ownership status vs snap test results
The second hypothesis was that tick-borne diseases would demonstrate greater prevalence in stray dogs than
pets.
There was a statistically significant relationship between stray dogs and positive canine TBDs results,
p<0.05, rejecting the null hypothesis. It is also thought that stray dogs are more susceptible to infection due
to poor nutrition, being unvaccinated and experiencing higher stress levels. This culminates in a reduced
ability of the immune system to mount an effective response increasing risk of infection [6]
4.6 Sex status vs snap test results
The final hypothesis was that more males would be affected by tick-borne diseases than females.
There was no statistically significant relationship between sex and positive snap test results, p>0.05,
accepting the null hypothesis. Klein, (2000) determined that male animals are more susceptible to
protozoan, fungal, bacterial, and viral infections, this susceptibility may be due to androgens modulating
immunity [37]. However, previous studies into E. canis showed no relationship between seroprevalence and
sex [16]. Our results may have been influenced by the small sample size and sample bias due to more
female participants than males, however it may also be that in this population there is no difference in
immune responses between males and females.
4.7 Improvements
Using the snap tests from IDEXX improved the sensitivity of the results as microscopic examination has
previously been suggested to be of limited sensitivity. No animals showed signs of infection on clinical
examination, therefore finding organisms on blood smear examination and positive snap test results may
indicate a degree of subclinical infection. Improving detection of infection would require use of multiple
diagnostic techniques, a combination of haematology, serology and molecular testing (PCR) to avoid any
misdiagnosis of the presence of parasites.
19
It has been shown by Bohm et al, 2006 and Schetters et al, 1998 that sampling from the ear vein can produce
better results for finding pathogens [38,39]. It is believed that capillary samples are the most diagnostic as it
is thought that the blood moves slower though these veins due to increased red blood cell membrane rigidity,
therefore red blood cells containing parasites congregate here [38]. In this study it was not possible to collect
blood from the ear.
A larger sample size, longer time for data collection and samples taken from different regions of Sri Lanka
would have improved this study. This would have provided more comprehensive results and reliable data
and allowed findings to be more transferrable to the country as a whole. This may be considered an area for
further research.
4.8 Future research
A sample bias existed in this study, all dogs brought to the BPT over the two week period were sampled,
however more data could have been recorded. The age and body condition of dogs could have been
included, although some studies suggest these are not significant risk factors for canine TBDs [12].
There is potential for further research into these factors affecting clinical signs throughout Sri Lanka.
Reduction in disease burden may be achieved by vector control. Townson et al, 2005 reported that in
countries with malaria, such as India and Sri Lanka, disease control programmes focusing on vector control
were highly effective. [1]. Tick control is likely to be difficult in Sri Lanka, as the huge population of
roaming dogs are unlikely to receive treatment or preventative therapy. It may be useful for future research
to examine whether tick control is a viable prevention strategy and its efficacy in preventing canine TBDs.
5.0 Conclusion
This project provides new and interesting evidence into the presence of at least 4 canine tick-borne diseases;
Anaplasma, Ehrlichia, Dirofilaria and Hepatazoon in a population of dogs in Colombo, Sri Lanka. To the
authors knowledge this is an area that has not been studied previously. This study has also proved that co-
infection with canine TBDs is present in Sri Lanka; this should be made aware to practitioners who may be
initiating treatment of canine TBDs. In order to gain a more reliable and comprehensive understanding of
canine TBDs in Sri Lanka further investigations need to be conducted using data from more locations and
with larger sample sizes.
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6.0 Acknowledgements
The author of this study would like to give thanks to the British Veterinary Association for the projects
acceptance of the Overseas Travel Grant 2014. The author would like to thank IDEXX laboratories for
providing 100 snap tests for this project, also to the Blue Paw Trust for allowing samples to be collected and
the neighbouring Pet Vet Clinic for allowing sample collection and use of the laboratory facilities for
sample analysis. Finally the author would like to thank Kate English for all her help with the project.
Word count: 3985
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8.0 Appendix
Please find attached the information sheet for the IDEXX 4Dx Plus snap test.