Prevalence and molecular characterization of zoonotic helminths in dogs.

A cross sectional study was designed to ascertain the prevalence of zoonotic helminths and protozoan parasites in dogs by employing conventional techniques and molecular characterization using polymerase chain reaction (PCR). Companion animals are reservoir hosts for helminths and protozoa species, and cohabitation with humans play a pivotal role in the transmission of zoonotic parasites to humans. A total of 510 faecal samples were collected from pet dogs belongs to various zones of Chennai city, Tamil Nadu, India and were processed by conventional techniques and molecular techniques. Out of 510 dog faeces, 121 samples were found positive for the parasitic eggs, prevalence rate was found to be 23.72%. Species-wise prevalence of the parasite was tabulated. PCR for the species-specific identification of the parasitic eggs was performed. The results revealed 38 samples were positive with product size of 540 bp specific for Ancylostoma caninum, 25 samples were positive which yielded a product size of 380 bp which is specific for Toxocara canis. None of the faecal samples tested were positive for Echinococcus granulosus which were positive for the presence of Taenia spp. eggs by microscopy. We recommend prevention and control measures focused on improving regular deworming, enhancing awareness of parasitic zoonotic diseases to minimize the transmission risk of parasitic zoonotic diseases from companion animals to humans. PCR can be widely used for species-specific identification of the zoonotic parasites.