Deer can contract mange, a skin disease caused by microscopic parasitic mites. This condition, medically known as sarcoptic mange in animals and scabies in humans, leads to significant skin irritation and hair loss. Mange occurs when these tiny external parasites burrow into the skin layers. While often associated with canids like foxes and coyotes, deer are susceptible to the mites that cause this contagious dermatological issue. The presence of mange in a deer population can indicate a decline in overall health, especially in areas with high animal density.
The Mite Responsible and Physical Symptoms
The cause of sarcoptic mange is the microscopic mite Sarcoptes scabiei, a burrowing parasite. The female mite tunnels into the epidermis, the upper layer of the deer’s skin, where she lays eggs. This activity triggers an inflammatory and allergic response in the host animal.
Visual symptoms are distinct. The most obvious sign is hair loss (alopecia), which often begins on the head, ears, and neck before spreading across the body. The affected skin becomes thickened, wrinkled, and covered in gray or white scabs and crusts, a condition called hyperkeratosis.
Infected deer exhibit scratching, rubbing, and chewing of the skin in an attempt to relieve the itching. This self-trauma frequently leads to open sores and secondary bacterial infections, which can give the skin a foul odor. As the condition progresses, a deer may appear lethargic, weak, and emaciated due to constant irritation and difficulty feeding.
How Mange Spreads Among Deer
Transmission occurs primarily through close physical contact between an infected deer and a healthy one. Direct contact, such as rubbing during social interactions or fighting, is an efficient way for the mites to transfer. High deer populations accelerate this spread due to the increased frequency of contact.
Mites can also be transmitted indirectly via a contaminated environment, referred to as fomites. Shared bedding sites, feeding areas, or rubbing posts can harbor mites that survive off a host for a short period, especially in cool, humid conditions. When an uninfected deer uses that location, the parasites can transfer to the new host.
The Sarcoptes scabiei mite is capable of infesting other mammals, including dogs and cats. In humans, contact with an infected deer can result in transient scabies. This self-limiting condition typically causes intense itching and a rash but is short-lived, as the animal-specific mite strain does not complete its life cycle on a human host.
Severity of Infection and What to Do
Mange can range from a localized, mild irritation to a severe, life-threatening condition. In advanced cases, extensive hair loss compromises the deer’s ability to regulate its body temperature, increasing the risk of hypothermia during colder months. The constant energy expenditure from scratching and fighting secondary infections can lead to emaciation and a weakened immune system.
While some deer with mild infestations may recover, the prognosis for an animal with severe, widespread lesions is often poor, sometimes resulting in death. If you encounter a deer exhibiting signs of mange, do not attempt treatment yourself. Administering veterinary medications to free-ranging wildlife is illegal and dangerous for both the animal and the person involved.
The correct action is to immediately report the sighting to your local state wildlife management agency, such as the Department of Natural Resources or Game Commission. These professionals assess the animal’s condition and determine if a management response is necessary. Also, avoid intentionally feeding wildlife, as concentrating animals increases the potential for disease transmission.