About 1 in 15 house cats carry parasite, study finds
Around 6.3 percent of cats across North America carry an intestinal parasite, a new study shows. The microscopic organism can infect people and cause giardiasis, commonly known as beaver fever. The study did not establish whether any cats transmitted the organism to people.
The findings appeared Wednesday in the journal PLOS One. Researchers analyzed feline stool samples collected between March 2022 and August 2023 across the United States and Canada. Nearly one in five infected felines carried strains that could jump to humans.
The organism causes an intestinal illness, according to the New York State Department of Health. People can catch it by swallowing contaminated water or touching infected surfaces.
Symptoms include stomach cramps, diarrhea, nausea, gas and dehydration. Some people show no symptoms. Signs appear one to two weeks after exposure and last two to six weeks. Infected felines can also show diarrhea. Many show no signs at all.
The study found clear infection patterns by age and season across North America:
- Kittens under 1 year old: 10.7 percent
- Senior felines: 1.3 percent
- Peak region: Midwest
- Lowest season: Summer
Male felines also tested positive more often than females. Researchers suggested the organism thrives in cool, moist weather. Kittens may face higher risks because their immune systems are still developing.
Dr. Anne Kimmerlein co-authored the study and spoke to ABC News about the results.
“Because some strains of Giardia can affect both animal and human health, understanding how commonly it occurs can help support earlier detection, appropriate treatment, and conversations about practical steps pet owners can take to help protect both their pets and their households,” Kimmerlein said.
Pet owners can lower risk by washing their hands after cleaning litter boxes. Owners should consult veterinarians if their pet tests positive.
Veterinary screening programs examine fecal samples to identify microscopic parasites before they cause serious complications. These standard laboratory checks help clinics recommend medications and sanitation practices.
Researchers noted the study reviewed samples sent for veterinary testing. Those tests might not reflect rates across all household pets in North America.
