Pet Columns, Office of Public Engagement, College of Veterinary Medicine at the University of Illinois at Urbana-Champaign

University of Illinois at Urbana-Champaign

U of I logoCollege of Veterinary Medicine

Back to search page.

Outdoor Cats: Truth and Consequences


Pet Column for the week of January 25, 2011

Related information:

Related site - Dr. Kenneth Welle

Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
Brittany Way
Information Specialist

You've probably heard that outdoor cats are bad for the bird population, but is that the whole story, the only argument for keeping your cat indoors?

Dr. Kenneth Welle, a veterinarian at the University of Illinois Veterinary Teaching Hospital, recently explained a variety of health impacts—on wildlife as well as on the cats—when cats are allowed to roam.

Feral and outdoor cats kill hundreds of millions of birds every year in the United States, according to the American Bird Conservancy. When cats are introduced as predators into a new environment, populations can often be devastated. Where populations are already dealing with predators, the devastation on the birds is often lessened because the birds may have natural defenses to protect themselves. Nevertheless, cats are a major predator that is often harmful to any bird population.

Many people think that placing a bell around the cat's neck will cause birds to disperse. The sound of a bell, however, does not trigger an alarm response in birds and often birds do not respond.

Cat owners should know that there are more reasons to keep cats indoors than preventing bird kills. Disease, cars, and predators are major threats to the life of an outdoor cat. The lifespan of a feral cat is two to three years, whereas an indoor cat will average 12 to 15 years, and often live to 20 years, according to Dr. Welle.

Diseases can also be more prevalent in outdoor cats. Vaccinations don't help for all the diseases of concern in outdoor cats. However, outdoor cats are just as likely to succumb to dogs, coyotes, cars, and parasites as they are to die from disease.

The myth that "keeping cats indoors stifles their nature" is not true. According to Dr. Welle, indoor environments can be complex enough to provide stimulation. Adding elements such as climbing structures, catnip sources, and toys can help keep the indoor environment satisfying to cats.

The impact of cats on the wildlife ecosystem extends beyond your backyard. In fact, cats can negatively affect conservation on a large scale. If you have questions or want more information, please contact your local veterinarian.