Housecats have long been fingered as voracious hunters, causing dozens of native-mammal extinctions in Australia alone.
But the purring pet predators bring with them another threat to wild animals, according to research published by Britain’s Royal Society: the spread of disease.
Scientists at the University of British Columbia in Canada said the prevalence of toxoplasmosis, which can cause flu-like symptoms in humans and cysts in wild animals, can be traced to the world’s estimated 600 million housecats, with the incidence of disease rising among wild animals in regions where pet cats are common.
While it has been long established that cats spread toxoplasmosis via their faeces and that wild animals are vulnerable to the disease, “the probable drivers of these prevalence patterns [of disease in wild animals] has received less attention,” the researchers said.
To figure out the puzzle, the team looked at hundreds of published studies of wild animals affected by toxoplasmosis, covering 238 species and over 40,000 animals, and found the prevalence of the T. gondii germ that causes the disease to be “positively associated with human population density and warmer temperatures at the sampling location.”
What that means is “pathogen pollution from free-roaming domestic cats likely plays a key role since, unlike wild cats, domestic cats are closely associated with humans.”
The researchers noted by comparison that “wildlife populations in pristine environments with exposure only to wild felids have a lower T. gondii prevalence than populations with increased exposure to domestic cats.”Show