Growths found on the skin of white-tailed deer are called fibromas. They are commonly referred to as skin tumors, or simply warts. These growths do not hurt the deer since they are usually non-cancerous tumors called either fibromas or papillomas. In both cases, the warts or tumors are caused by viruses. The difference between the two is that fibromas grow either from the skin or from the layer beneath, while papillomas grow only from the skin. An infection with fibromas is called fibromatosis.
Cutaneous Fibromas or (warts) are caused by a naturally occurring virus of the deer’s skin. Once the virus enters the skin, warts begin to form. As they increase in size, the surrounding skin can become hairless and grayish in color and often is scratched and bleeding. Others have a black, dry, hard surface that may look like the head of a cauliflower. The bigger ones tend to hang like small punching bags because of their weight. The number of warts can vary from one to several hundred, forming clumps, and can cover most of the deer’s body.
Fibromas can appear anywhere on deer, but tend to grow around the eyes, neck, face, and forelegs. Occasionally, there are so many growths that they join into a huge mass. However, this is very rare based on the number of reported cases.
How the disease is transmitted to the deer in the wild is not fuly known. Possibly, either from an infected deer or vegetation which has been rubbed or brushed by an infected deer. The fact that the disease is highest among bucks suggests that fighting is a means for spreading the disease. Biting insects may possibly be responsible since many viruses are transmitted by insect.
Fibromatosis in deer is not usually deadly, and is not known to infect humans. It's main significance is in it's unsightly appearance. Though they isolated to the skin and don't harm the meat, fibromas are repulsive to most hunters, making the thought of eating the meat undesirable.
In summary, cutaneous fibromas are merely skin blemishes on a white-tailed deer. They are of no significance to the health of the deer population.