Zombie Squirrels in Backyards

Squirrel fibroma virus creates visible skin fibromas in some squirrels but does not threaten humans.

Zombie Squirrels Appear in Backyards Across North America

Residents in Canada and the United States report seeing squirrels with large skin growths that look alarming. Scientists say the cause is squirrel fibroma virus, a poxvirus that mainly affects squirrels and rabbits. The tumors are fibromas and appear on the head or limbs. The virus spreads mainly through bites from mosquitoes and fleas, and sometimes through close contact with an infected animal. Most squirrels recover, and the illness is usually limited to the skin.

Officials say the infection does not threaten human health and has not reduced squirrel populations in places where it is common. There is confusion because several viruses have similar names. Experts call for clearer labeling of these diseases and plain language in updates. People are advised not to handle wildlife and to observe from a distance.

Online readers react to dramatic images more than to science. A striking photo can turn a natural wildlife illness into fear of a zombie animal. The fact remains that this virus is a local health issue for squirrels and does not threaten people.

Clear communication matters. Wildlife agencies should share plain language that explains how the virus spreads and what to expect for animal recovery. The naming confusion in wildlife diseases shows the need for standard terms and careful updates to the public.

Highlights

More guidance will follow as experts monitor wildlife health.