Diseases and Parasites of Maryland Deer

Brain Abscesses

This fatal disease is a bacterial infection of the deer’s brain caused by various bacteria, primarily Actinomyces pyogenes. Bacteria typically enters the brain through skin infections near the antlers; therefore antlered bucks are more prone to having this malady due to antler rubbing and sparring. This disease usually occurs during the time period immediately following velvet shedding through antler drop (September through March).

Infected deer exhibit neurological problems, such as circling and lack of coordination, and some deer may exhibit strange behavior such as walking toward humans. Deer may be in poor physical condition. Total mortality in the deer population is probably low with adult antlered bucks being at higher risk than females and yearling bucks. Deer with brain abscesses should not be consumed.


Photographs are used with the permission of the Southeastern Cooperative Wildlife Disease Study located at the University of Georgia, College of Veterinary Medicine.

For more information about white-tailed deer parasites and diseases, visit the Southeastern Cooperative Wildlife Disease Study Web site. The publication “Field Manual of Wildlife Diseases in the Southeastern United States” (third edition) by William R. Davidson and Victor F. Nettles explains and describes in detail parasites and diseases of southeastern birds and mammals. It is available for purchase through the website listed above.

Maryland Department of Natural Resources
Wildlife and Heritage Service
Tawes State Office Building, E-1
Annapolis MD 21401
Toll-free in Maryland: 1-877-620-8DNR, Ext. 8540

E-Mail: customerservice.dnr@maryland.gov

Diseases and Parasites of Maryland Deer