| Shelby Credit: Heidi-Ann Fourkiller |
The study—the first to analyze so many wildlife species over a global scale—also highlights how healthy ecosystems can protect against these types of pathogens.
The researchers, led by UBC faculty of forestry adjunct professor Dr. Amy Wilson, examined 45,079 cases of toxoplasmosis in wild mammals—a disease that has been linked to nervous system disorders, cancers and other debilitating chronic conditions—using data from 202 global studies.
They found wildlife living near dense urban areas were more likely to be infected.
“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,” says Dr. Wilson.
“This finding is significant because by simply limiting free roaming of cats, we can reduce the impact of Toxoplasma on wildlife.”
One infected cat can excrete as many as 500 million Toxoplasma oocysts (or eggs) in just two weeks. The oocysts can then live for years in soil and water with the potential to infect any bird or mammal, including humans. Toxoplasmosis is particularly dangerous for pregnant people.