Recent photos of deer with disturbing black growths have sparked concern across the U.S., with social media users calling them “mutant deer.” These images, shared from states like Pennsylvania and Wisconsin, have triggered fears of a new wildlife health crisis.

However, wildlife experts clarify this is not a new or mysterious condition. The growths are caused by a well-known virus called deer fibroma, a species-specific papillomavirus that only affects deer.

The virus causes firm, dark, hairless warts of varying sizes on a deer’s skin. While the appearance is alarming, it is not related to more serious diseases like chronic wasting disease. The condition is typically benign.

Deer fibroma poses no risk to human health. The virus spreads among deer through direct contact at shared rubbing posts, feeding areas, and bedding grounds.

In most cases, a deer’s immune system will fight off the virus over several months, and the growths will disappear without any need for intervention. Treatment for wild deer is neither practical nor necessary.

The recent attention is largely due to social media amplifying these sightings. Furthermore, experts note that climate change is expanding the range of ticks and mosquitoes, which can exacerbate the spread of various wildlife diseases.

While the deer’s appearance is unsettling, experts urge the public not to be alarmed. The condition is natural, often temporary, and not a sign of an ecological crisis. Officials recommend leaving affected animals undisturbed.