Molecular characterization and risk factors analyses of zoonotic gastrointestinal nematodes in pet and semi-pet dogs in Haryana, India

BACKGROUND: Dogs play an important role in the transmission of zoonotic parasites to humans. Among these, gastrointestinal (GI) helminths are widely prevalent and pose a significant public health risk. This study investigated the prevalence, molecular characterization and risk factors analyses of gastrointestinal nematodes in pet and semi-pet dogs in Haryana, India, to assess their potential zoonotic relevance. RESULTS: A total of 310 faecal samples were collected from pet and semi-pet dogs from five randomly selected blocks of Hisar district of Haryana, India and examined for the presence of zoonotic GI nematodes. Of these, 77 samples (24.85%) were found positive for zoonotic GI nematodes. Among the positive samples, 73 (94.80%) exhibited single parasitic infection with Ancylostoma spp. and three (3.90%) with Toxocara spp., whereas mixed infection with both parasites was observed in only one (1.30%) sample. A Toxocara spp. worm was also observed in one of the Toxocara spp. positive faecal samples. Molecular characterization based on the cox1 gene identified Ancylostoma spp. as Ancylostoma caninum and Toxocara spp. as Toxocara canis. Phylogenetic analysis revealed that the A. caninum sequences of the present study formed a distinct clade compared to sequences reported from other countries. In case of T. canis, no geographical segregation of clades was observed and the sequences generated herein assorted with the sequences of China, Poland, Russia and Brazil origin. Univariate logistic regression analysis identified breed, deworming status, living conditions of the dog, type of housing, contact with stray dogs, history of allotriophagia, vaccination status and faecal score to be significantly associated (p < 0.05) with GI nematodosis in dogs. Multivariate analysis identified history of allotriophagia (p = 0.0158) as the major significant risk factor. CONCLUSIONS: The high prevalence of zoonotic GI nematodes underscores the potential role of pet and semi-pet dogs as sources for these parasites. This highlights the probable risk of transmission of these zoonotic parasites to humans, particularly in settings with close human-dog interactions. Raising awareness among dog owners and caretakers regarding zoonotic GI nematodes and their routes of transmission could act as a key for controlling and preventing zoonotic GI nematodosis in dogs under the One-Health framework.