Mutant deer can be spotted across the US: What to know

Deer across the U.S. are showing alarming tumour-like growths known as deer cutaneous fibroma or deer warts.

Deer across the United States have been showing strange, tumour-like growths on their bodies, alarming wildlife watchers and social media users who have been documenting the unusual sightings.

Strange tumor-like growths, termed deer warts, are appearing on deer in the U.S., alarming wildlife experts. (X)

These deformities, sometimes appearing as large bubbles or warts on the face, neck, or legs, have been photographed from New York to Pennsylvania to Wisconsin over the past two months.

Wildlife experts say the culprit is a condition known as deer cutaneous fibroma, more commonly referred to as “deer warts.” The disease is caused by a papillomavirus that spreads among deer populations nationwide, and reports of it are increasing this summer.

“Papillomas are most frequently seen during the late summer and into the fall, probably due to increased biting insect activity during this time of year,” the Washington Department of Fish and Wildlife explained.

“These temperature changes are resulting in diseases that were never endemic in certain areas to become endemic,” Dr. Omer Awan of the University of Maryland School of Medicine told Daily Mail.

What is deer wart?

Deer warts can range from small pea-like bumps to growths as large as a football. They are usually gray, black, or flesh-colored and often hairless. Though visually disturbing, the condition is rarely fatal.

Though in most cases, a deer’s immune system eventually clears the virus, and the warts shrink and disappear within a few months. However, in rare cases, if the growths become too large or get infected with bacteria, they can interfere with the animal’s ability to see or eat.

Wildlife veterinarian Dr. Kristin Mansfield told FOX13, “Deer can spread the virus if they share the same feeding areas, sleeping spot, or rubbing posts, usually a tree males use to mark their territory during mating season.” He also noted the virus cannot spread to humans or other animals since it is species-specific.

Notably, scientists have been studying deer warts since as early as the 1950s, but they have become more evident in recent years, partly due to climate change range and partly due to social media.