Frequency of Helminth Eggs in Faeces of Puppies Living in Urban or Rural Environments of Mexico City

The dog, Canis familiaris, a domestic animal that maintains close contact with humans and other animals, is considered as a potential source of zoonotic parasites. The current study aimed to determine the frequency of helminth eggs in feces of puppies of dog living in urban or rural environments of Mexico City between spring and summer of 2013. Stool samples (n=180) were analyzed by sedimentation with formalin-ether. Samples were collected from puppies living in the urban zone (n=90; stray animals) or in the rural environment (n=90; stray animals, animals with owner and animals confined to a canine control center). Eggs of Toxocara canis (41%), Ancylostoma caninum (8%) and Dipylidium caninum (3%) were found in the rural environment but none in the urban zone. A frequency of 19% of Toxocara eggs was found in the canine control center, while, in stray puppies, the frequency was of 12% and 10% in animals with owner. Eggs of Toxocara were found in 33% samples of puppies with history of antiparasitic treatment. This study supports the observation of helminth population reduction in urban environments. Further studies are needed to identify the factors that affect the development and transmission of helminth eggs in urban environments.