October 01, 2020
Study finds parasites common in dog parks
Dogs that visit dog parks may be more likely to have parasites than dogs in the general pet population, according to survey results.
Through tests on feces, researchers found more than one-fifth of dogs at parks across the country were shedding parasites.
Dr. Susan E. Little, who is a parasitology professor in the Oklahoma State University College of Veterinary Medicine, described results of a study by Oklahoma State and Idexx that identified parasites in feces collected from 85% of parks visited across the U.S. She thinks that figure underestimates the prevalence because of limited sampling per park.
“Many of us have already been made aware or probably could have anticipated that parasites are really common at dog parks,” she said.
Dr. Little described the study results in an Elanco-sponsored presentation Aug. 21 for the AVMA Virtual Convention 2020.
Dr. Little also noted that one survey conducted in 2017-18 found that 37% of people bring their dogs on road trips, almost double the proportion who did 10 years earlier.
“Dogs are invited, encouraged to go many more places than was the case just a few years ago,” she said. “And most of us see this as a very good thing.”
But parasites travel with dogs, she said.
In the new study, researchers collected fecal samples from 3,000 dogs over six weeks in July and August 2019 at 288 dog parks across the U.S., with owner permission and participation in questionnaires.
Overall, about 21% of dogs had some parasites. Citing a study from 2009, Dr. Little said about 12% of dogs presented for wellness care at that time were positive for parasites.
Hookworms, whipworms, and Giardia species were the most common among the dogs in dog parks in the new study, although some were infected with roundworms, coccidia, or tapeworms. Most dog parks are open to the public without screening for animal health, Dr. Little said.
The researchers found parasites in the feces of visiting dogs at about 90% of dog parks in the Southeastern U.S., 87% in the Midwest, 80% in the Northeast, and 79% in the West, Dr. Little said.
The South also had the highest rates of positive tests for hookworms, affecting 15% of dogs and 72% of parks, versus a low in the West of 1.5% of dogs and 17% of parks. The Miami area had a particularly high prevalence, with hookworms present in more than one-third of dogs sampled, Dr. Little said.
The researchers found about equal Giardia prevalence across the U.S., with positive samples from about 13% of dogs and about three-quarters of parks. Dr. Little noted many dog parks had wading pools, sprinklers, or splash pads during the summer sampling period, and Giardia species do well in water.
The questionnaire results combined with the sampling also found lower hookworm prevalence among dogs on heartworm preventives, at 6% rather than almost 12% of all dogs. When dog owners said their pets were on heartworm preventives, most of the dogs positive for hookworms were antigen positive only and not shedding eggs, and they may have been reinfected between doses.