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