Dog-walking behaviours affect gastrointestinal parasitism in park-attending dogs

BACKGROUND: In urban parks, dogs, wildlife and humans can be sympatric, introducing the potential for inter- and intra-specific transmission of pathogens among hosts. This study was conducted to determine the prevalence of zoonotic and non-zoonotic gastrointestinal parasites in dogs in Calgary city parks, and assess if dog-walking behaviour, park management, history of veterinary care, and dog demographics were associated with parasitism in dogs METHODS: From June to September 2010, 645 questionnaires were administered to dog owners in nine city parks to determine behavioural and demographic factors, and corresponding feces from 355 dogs were collected. Dog feces were analyzed for helminth and some protozoan species using a modified sugar flotation technique and microscopic examination, a subsample was analyzed for Giardia spp. and Cryptosporidium spp. using a direct immunofluorescence assay. Descriptive and multivariate statistics were conducted to determine associations among behaviours, demographics, and parasite prevalence and infection intensities RESULTS: Parasite prevalence was 50.2%. Giardia spp. (24.7%), Cryptosporidium spp. (14.7%), and Cystoisospora spp. (16.8%) were the most prevalent parasites. Helminth prevalence was low (4.1%). Presence of Giardia spp. was more likely in intact and young dogs; and infection with any parasite and Giardia spp. intensity were both positively associated with dogs visiting multiple parks coupled with a high frequency of park use and off-leash activity, and with being intact and young. Cryptosporidium spp. intensity was associated with being intact and young, and having visited the veterinarian within the previous year CONCLUSIONS: Our results indicate a higher overall prevalence of protozoa in dogs than previously found in Calgary. The zoonotic potential of some parasites found in park-attending dogs may be of interest for public health. These results are relevant for informing park managers, the public health sector, and veterinarians.