Canine vector-borne diseases in India: a review of the literature and identification of existing knowledge gaps

Despite the combination of favourable climate for parasites and vectors, and large populations of stray dogs, information concerning the epidemiology, diagnosis and management of canine vector-borne diseases in India is limited. However, with the country's expanding economy and adaptation to western culture, higher expectations and demands are being placed on veterinary surgeons for improved knowledge of diseases and control. This review aims to provide an overview of the current state of knowledge of these diseases in India and identify existing knowledge gaps in the literature which need to be addressed. The available literature on this subject, although limited, suggests that a number of canine vector-borne diseases such as filariasis, babesiosis and ehrlichiosis are endemic throughout India, as diagnosed mostly by morphological methods. Detailed investigations of the epidemiology and zoonotic potential of these pathogens has been neglected. Further study is essential to develop a better understanding of the diversity of canine vector-borne diseases in India, and their significance for veterinary and public health

The prevalence and distribution of gastrointestinal parasites of stray and refuge dogs in four locations in India

A gastrointestinal parasite survey of 411 stray and refuge dogs sampled from four geographical and climactically distinct locations in India revealed these animals to represent a significant source of environmental contamination for parasites that pose a zoonotic risk to the public. Hookworms were the most commonly identified parasite in dogs in Sikkim (71.3%), Mumbai (48.8%) and Delhi (39.1%). In Ladakh, which experiences harsh extremes in climate, a competitive advantage was observed for parasites such as Sarcocystis spp. (44.2%), Taenia hydatigena (30.3%) and Echinococcus granulosus (2.3%) that utilise intermediate hosts for the completion of their life cycle. PCR identified Ancylostoma ceylanicum and Ancylostoma caninum to occur sympatrically, either as single or mixed infections in Sikkim (Northeast) and Mumbai (West). In Delhi, A. caninum was the only species identified in dogs, probably owing to its ability to evade unfavourable climatic conditions by undergoing arrested development in host tissue. The expansion of the known distribution of A. ceylanicum to the west, as far as Mumbai, justifies the renewed interest in this emerging zoonosis and advocates for its surveillance in future human parasite surveys. Of interest was the absence of Trichuris vulpis in dogs, in support of previous canine surveys in India. This study advocates the continuation of birth control programmes in stray dogs that will undoubtedly have spill-over effects on reducing the levels of environmental contamination with parasite stages. In particular, owners of pet animals exposed to these environments must be extra vigilant in ensuring their animals are regularly dewormed and maintaining strict standards of household and personal hygiene

A survey of canine filarial diseases of veterinary and public health significance in India

Background. Dirofilaria spp., Acanthocheilonema spp. and Brugia spp. have all been reported in Indian dogs. In previous studies, diagnosis was made by morphological identification only. This is the first geographically stratified cross-sectional study in India to determine the prevalence and geographical distribution of canine filarial species of veterinary and public health importance, using a combination of conventional and molecular diagnostic techniques. Results. A total of 139 from 525 dogs (26.5%; 95% CI 22.7, 30.3) were positive for microfilariae. The most common species of canine filaria identified in this study was A. reconditum (9.3%) followed by D. repens (6.7%) and D. immitis (1.5%). Three out of 525 dogs were found to have mixed infections on PCR. The morphological and molecular evidence on the sequence of the 18S gene and phylogenetic analysis of the ITS-2 region provided strong evidence that the canine microfilariae discovered in the Himalayan city of Ladakh belong to a novel species of Acanthocheilonema. Two dogs in Ladakh were also found to have mixed infections of the novel species described above and a unique microfilaria which morphologically resembled Microfilaria auquieri Foley, 1921. Conclusions. At least six species of filarial nematode are now known to infect dogs in India, two of which were reported for the first time in this study. The study also confirms and extends the geographical distribution of canine heartworm (D. immitis) which overlaps with D. repens, emphasising the importance for veterinary clinicians and diagnostic laboratories to utilise immunodiagnostic tests that will not cross-react between those two filarial species. From a public health viewpoint, the distribution and prevalences of these nematodes warrant an appropriate prophylaxis to be administered to dogs

Epidemiological, clinical, haemato-biochemical and therapeutic evaluation of canine trypanosomosis in Mumbai

Evaluation of 20 confirmed clinical cases of canine trypanosomosis caused by Trypanosoma evansi in Mumbai from June 2012 to May 2013 was done to compile the basic information on parasitological, epidemiological, clinical, clinico-pathological and chemotherapeutic aspects. The disease was predominantly found in the localities having substantial equine and bovine population thus underlining the potential source for canine cases. Molecular analysis of few representative samples also confirmed the ability of the organisms to crossover from one species to other species of host. The disease was characterized by clinical signs such as depression, anorexia, anaemia, fever, splenomegaly, hepatomegaly and oedema of legs and paraclinical findings such as low levels of TEC, Hb and PCV indicating anaemic trend, elevated levels of alkaline phosphatase, AST, ALT and hyperglobulinaemia associated with reversing of albumin: globulin ratio. Hypoglycaemic trend noted in the study was found positively correlated with intensity of parasitaemia. Blood glucose levels were inversely related to degree of parasitaemia. The chemotherapeutic options, diminazeneaceturate and antrycideprosalt although cleared parasitaemia but failed to provide complete recovery, as 50% of cases eventually died in spite of specific chemotherapy suggesting some secondary involvement in the disease entity

A survey of canine tick-borne diseases in India

Background: There are few published reports on canine Babesia, Ehrlichia, Anaplasma, Hepatozoon and haemotropic Mycoplasma infections in India and most describe clinical disease in individual dogs, diagnosed by morphological observation of the microorganisms in stained blood smears. This study investigated the occurrence and distribution of canine tick-borne disease (TBD) pathogens using a combination of conventional and molecular diagnostic techniques in four cities in India. Results: On microscopy examination, only Hepatozoon gamonts were observed in twelve out of 525 (2.3%; 95% CI: 1.2, 4) blood smears. Using polymerase chain reaction (PCR), a total of 261 from 525 dogs (49.7%; 95% CI: 45.4, 54.1) in this study were infected with one or more canine tick-borne pathogen. Hepatozoon canis (30%; 95% CI: 26.0, 34.0) was the most common TBD pathogen found infecting dogs in India followed by Ehrlichia canis (20.6%; 95% CI: 17.2, 24.3), Mycoplasma haemocanis (12.2%; 95% CI: 9.5, 15.3), Anaplasma platys (6.5%; 95% CI: 4.5, 8.9), Babesia vogeli (5.5%, 95% CI: 3.7, 7.8) and Babesia gibsoni (0.2%, 95% CI: 0.01, 1.06). Concurrent infection with more than one TBD pathogen occurred in 39% of cases. Potential tick vectors, Rhipicephalus (most commonly) and/or Haemaphysalis ticks were found on 278 (53%) of dogs examined. Conclusions: At least 6 species of canine tick-borne pathogens are present in India. Hepatozoon canis was the most common pathogen and ticks belonging to the genus Rhipicephalus were encountered most frequently. Polymerase chain reaction was more sensitive in detecting circulating pathogens compared with peripheral blood smear examination. As co-infections with canine TBD pathogens were common, Indian veterinary practitioners should be cognisant that the discovery of one such pathogen raises the potential for multiple infections which may warrant different clinical management strategies

Molecular and morphological characterisation of Echinococcus from food producing animals in India

In view of the medical, veterinary and economic importance of hydatid disease in India, our study aimed to determine the prevalence and genotypes of Echinococcus present in domestic livestock in India. Out of 21,861 animals examined, cattle were found with the highest prevalence of hydatid cysts (5.10%) followed by buffaloes (3.81%), pigs (0.87%) and sheep (0.075%). Phylogenetic analysis of the cytochrome oxidase-1 gene revealed that the buffalo strain or G3 genotype was the predominant genotype (29/46) in all species of livestock followed by the cattle strain or G5 genotype (9/46), the G1 genotype or the common sheep strain (6/46) and the G2 genotype or Tasmanian Sheep strain (2/46). The ability of the G3 (buffalo) and G5 (cattle) genotypes of Echinococcus granulosus to infect and produce fertile hydatid cysts in pigs was also demonstrated for the first time. Both morphological and molecular results support earlier studies suggesting that Echinococcus of buffalo origin is phenotypically and genetically similar to the sheep (G1) and Tasmanian Sheep (G2) strains of Echinococcus, which adds further evidence to support its recognition as one species, viz., E. granulosus sensu stricto. Our molecular, morphological and biological characteristics also support earlier studies suggesting that Echinococcus of cattle origin, designated the G5 genotype, should be recognised as a separate species, viz. Echinococcus ortleppi. Finally, the study reveals that the prevalence of hydatidosis in urban centres in India has been showing a consistently declining trend over the past few decades, possibly owing to economic development and improved government legislation of abattoirs

Toward the formation of a Companion Animal Parasite Council for the Tropics (CAPCT)

Submitted by Adagilson Silva ([email protected]) on 2017-11-17T17:41:53Z No. of bitstreams: 1 25963851 2015 tra-tow.oa.pdf: 360365 bytes, checksum: d5f5f51d2c2737f977b0906b3f688478 (MD5)Approved for entry into archive by Adagilson Silva ([email protected]) on 2017-11-17T18:49:35Z (GMT) No. of bitstreams: 1 25963851 2015 tra-tow.oa.pdf: 360365 bytes, checksum: d5f5f51d2c2737f977b0906b3f688478 (MD5)Made available in DSpace on 2017-11-17T18:49:35Z (GMT). No. of bitstreams: 1 25963851 2015 tra-tow.oa.pdf: 360365 bytes, checksum: d5f5f51d2c2737f977b0906b3f688478 (MD5) Previous issue date: 2015-05-13Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Recife, PE, BrasilThis letter advises the imminent formation of the Companion Animal Parasites Council for the Tropics (CAPCT). The CAPCT consists of region-specific (e.g., Asia-Pacific, Latin America and Caribbean, Africa) experts comprising academics, veterinarians, parasitologists, physicians and allied industry partners that will work together to inform, guide and develop best-practice recommendations for the optimal diagnosis, treatment and control of companion animal parasites in the tropics, with the aim of protecting the health of pets and that of the public