We get LOTS of photos of deer with wart-like, hairless tumors on their brown coats. These unsightly masses are more often than not cutaneous fibromas. They can develop anywhere on the body (see attached photos). Fibromas are caused by a virus. The virus is an obligate inhabitant of a deer’s skin and poses no known threat to people or domestic animals. Transmission is thought to occur through biting insects and possibly by direct contact with other infected deer or various contaminated materials that might scratch the skin allowing the virus a way in.
While ugly and in some cases grotesque, fibromas are merely surface blemishes as they do not spread to internal organs. In most cases, fibromas are small and resolve on their own. If fibromas are large, numerous, or in critical locations (eyes, mouth, etc.), they can result in significant disease and death. There is no treatment for fibromas in wild deer. As stated the virus associated with fibromas does not infect humans so the only concern for hunters would be fibroma with a secondary bacterial infection rendering a deer unfit for consumption.
By: J.T. Fleegle
Wildlife Biologist, Deer & Elk Management Section
Pennsylvania Game Commission