Indoor or outdoor cats? A new study finally settles the debate


A new study finally puts an end to the debate between outdoor cats and indoor cats. Inside, all the way. No exceptions – and for more reasons than you think.

The study, published in the journal Frontiers in Ecology and Evolution, says letting our cats roam free and go outside isn’t just bad for the birds – it also puts all kinds of wildlife, cats themselves and owners in serious danger. Here’s what you need to know.

For the study, led by the University of Maryland, researchers kept tabs on domestic cats and their interactions when they roam freely outdoors. Using a camera-trap survey with 60 motion-activated wildlife cameras spread across 1,500 sampling sites, the researchers found that the cats interacted with several wild animals that put their own health at risk.

“We found that the average domestic cat in DC has a 61% chance of being found in the same space as raccoons – America’s most prolific vector of rabies – 61% spatial overlap with red foxes and 56% overlap with Virginia opossums, which can also spread rabies,” said Daniel Herrera, lead author of the study and Ph.D. student in the Department of Environmental Science and Technology (ENST) of the UMD. “By leaving our cats outside, we significantly compromise their health.”

But cats facing a bad outcome aren’t the only thing the researchers found. When cats are in high-risk areas for things like rabies or toxoplasmosis, their owners are also at risk of contracting these diseases.

The Cat Count survey also found that when outdoor cats went outside freely, they went into the same spaces as small wild animals like rabbits, squirrels and mice. Not only does this increase their risk of disease and ours, but it has been bad for the ecosystem.

“Since humans largely influence where cats are located in the landscape, they also dictate the degree of risk these cats encounter and the amount of damage they cause to local wildlife,” Herrera said. Birds, rabbits, squirrels, oh my.

So what should cat owners do? Herrera encourages cat owners to keep their pets indoors and avoid potential crossbreeding with native wildlife. It’s better for cats, better for us humans, and better for the ecosystem too. Maybe an apology with Mittens will go a long way.