Study Finds High Levels of Intestinal Parasites in U.S. Dog Parks

During a session at the Fetch dvm360® virtual conference, Michael W. Dryden, DVM, PhD, DACVIM (parasitology), emeritus professor at Kansas State University, shared these findings. The study, known as DOGPARCS (Detection Of Gastrointestinal Parasitism At Recreational Canine Sites), was conducted from July to August 2019 and involved sampling canine feces in 30 metropolitan areas. Each of the participating parks yielded 10 fecal samples from different households, excluding those with professional dog walkers.

Dryden emphasized the importance of advanced testing methods, such as zinc sulfate centrifugal flotation and coproantigen immunoassays. These techniques are crucial for accurate detection of parasites, particularly whipworms, which can often be missed by traditional methods.

Data revealed that 1 in 5 dogs tested positive for parasites, with variability across regions: 90% of parks in the South, 87% in the Midwest, 80% in the Northeast, and 79% in the West tested positive. Hookworms were the most common parasites identified, and concerns about multidrug-resistant (MDR) strains continue to grow, particularly those originating from greyhound racing environments. Dryden noted that these resistant types pose challenges as they do not respond to traditional treatment options.

Whipworms and Giardia were also prevalent in the sampled parks. Dryden argued that whipworms are often underdiagnosed due to the limitations of standard fecal flotation tests. He noted that Giardia is commonly found in dog parks but reassured attendees regarding its zoonotic potential, explaining that transmission from dogs to humans has not been conclusively documented in North America.

The study also revealed that many dog owners reported their pets were on preventive medications but still had detectable levels of parasitism. This raises questions about compliance and effectiveness, prompting Dryden to recommend regular fecal testing for dogs that frequent parks. He suggests that veterinarians approach discussions about prevailing parasites positively to enhance pet owner awareness and compliance with preventive measures.

The findings from this extensive study underscore the need for greater awareness of the risks associated with dog parks and the importance of regular veterinary care to manage and prevent parasitic infections in dogs.