Cutaneous Fibromas: A Closer Look (Warts & All)
Cutaneous fibromas, more commonly called deer warts by hunters,
are occasionally observed on harvested deer. The fibromas are
pealing, especially when they appear in large numbers. "Grotesque"
is a common description of these harmless skin blemishes. The
fibromas are found in deer herds from a majority of states in the
nation. As a result, they are considered to exist in the entirety
of the white-tailed deer range.
According to Diseases and Parasites of the White-tailed
Deer, published by the Tall Timbers Research Station, R. F.
Shope was the first wildlife investigator to actually find the
specific virus. Shope was also the first researcher who
experimentally infected deer with the viral agent. He found that
the fibromas normally appeared at about 7 weeks after inoculation
and that they began to regress after 2 months in most deer. Because
of his work with infectious cutaneous fibromas, a commonly accepted
name for the growths is Shope's fibroma.
Fibromas are caused by a virus which is thought to be
transmitted by various biting insects. However, another possible
means of transmission of the viral agent is direct contact through
any assortment of contaminated objects which may scratch or
penetrate the skin of the deer.
The actual fibromas are gray or black in color and
range in size from less than one-half inch to 8 inches or greater
in diameter. The warty growth is covered by leathery, hairless skin
that can appear as a single growth or in multiple clumps. Reports
of over 200 fibromas have been confirmed on a single deer. Although
the fibromas can be found on all areas of the body, the most common
locations are the head, neck, and shoulders.
Rarely do fibromas cause deer any problems, but occasionally the
location of a large single or multiple clump of fibromas can
interfere with sight, eating, breathing, or even affect the ability
of the deer to walk. Occasionally, the larger fibromas acquire a
bacterial infection through a break in the skin. If you cut into a
fibroma, you will find it a solid mass which has a white color
throughout the growth. The attachment of the fibroma is limited to
the skin and no evidence of it can normally be found in the muscle.
Fibroma presence is typically not detectable after skinning the
An array of wart-like viruses also appears on
domestic livestock. These viruses are different from the ones found
on white-tailed deer, therefore spreading of the deer fibromas to
livestock is considered to be of no consequence.
No human infection from cutaneous fibromas has been reported.
The only concern for hunters would be from an animal with extensive
bacterial infection, which would render the deer unsuitable for
human consumption. These animals would be readily apparent due to
the unpleasant exudate produced at the infection site.
In summary, cutaneous fibromas are merely skin blemishes of
white-tailed deer. They are of no significance to the health of the