FRIDAY, Nov. 12, 2021 (HealthDay News) -- Letting your cat roam outside could spread a potentially deadly parasite to local wildlife, researchers warn.
The parasite Toxoplasma gondii causes a disease called toxoplasmosis, which has been linked to nervous system disorders, cancer and other serious chronic conditions in humans.
"As increasing human densities are associated with increased densities of domestic cats, our study suggests that free-roaming domestic cats -- whether pets or feral cats -- are the most likely cause of these infections," said study leader Dr. Amy Wilson, a veterinarian and adjunct professor in forestry at the University of British Columbia in Vancouver, Canada.
As well as wildlife, the parasite can infect humans and is particularly dangerous for pregnant women.
For the new study, researchers analyzed data on more than 45,000 cases of toxoplasmosis in wild mammals and found that those in densely populated areas were more likely to be infected.
"This finding is significant because by simply limiting free roaming of cats, we can reduce the impact of Toxoplasma on wildlife," Wilson said in a university news release.
One infected cat can excrete as many as 500 million Toxoplasma eggs in its feces in just two weeks. The eggs can survive for years in soil and water with the potential to infect any bird or mammal, including humans.
If an animal is healthy, the parasite rarely causes direct harm. But it can cause illness and even death in animals with weakened immune systems.
Healthy forests, streams and other ecosystems can filter out dangerous pathogens like Toxoplasma, according to the authors.
"We know that when wetlands are destroyed or streams are restricted, we are more likely to experience runoff that carries more pathogens into the waters where wild animals drink or live," Wilson said. "And when their habitats are healthy, wildlife thrives and tends to be more disease-resistant."
Studies like this one are a reminder that all ecosystems are linked, the authors noted.
"There is a growing recognition among forest science professionals and other groups that protecting biodiversity and the ecosystems it supports is an efficient and economical approach to reducing disease transfer between wildlife, domestic animals and humans," Wilson said. "Conservation is really preventative medicine in action."
The findings were published recently in the journal Proceedings of the Royal Society B: Biological Sciences.
More information
The U.S. Centers for Disease Control and Prevention has more on toxoplasmosis.
SOURCE: University of British Columbia, news release, Nov. 10, 2021
