Households with more than one cat should beware when it comes to intestinal parasites, a new study notes. 

Researchers from the Institute for Parasitology at the University of Veterinary Medicine in Vienna screened cats across Austria for single-cell intestinal parasites, or enteric protozoa, to assess the prevalence of parasites. Of the 298 cats sampled, 56 tested positive with at least one intestinal parasite.

The study was published in the May issue of Parasitology Research.

Researchers screened fecal samples from private households, boarding facilities, and animal shelters. The most common parasite found was Giardia.

The highest rate of positive samples (56 out of 298) was registered in houses with more than one cat; kittens were more at risk.

“Young animals must first come to terms with the pathogen and are not yet immune, which makes it possible for the pathogen to persist more stubbornly. When the animals excrete the parasite via feces, they infect other cats. This gives households with more than one cat a higher risk of infection," said researcher Barbara Hinney, PhD.

Giardia, which infect small intestines, were the most commonly found parasite with more than 12% positive samples.

"We mostly found species of Giardia that occur only in cats. There was one species that also exists in humans. The possibility of transmission from cats to humans can therefore not be excluded," Hinney added.