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Conservation > Fish & Wildlife Diseases Mange

For questions/concerns about this disease in humans, please call your doctor or the Montana Department of Public Health and Human Services  (DPHHS).

For questions about this disease/parasite in wildlife, please call the FWP Wildlife Health Lab at (406) 577-7882.

Cause

Mange is a broad term for diseases of the skin in animals, caused by mites. Sarcoptic mange, which is most common in coyotes, foxes and wolves in North America, is caused by a tissue-burrowing mite called Sarcoptes scabiei (Stitt, 2011). Demodectic mange, caused by mites of the genus Demodex, is usually found in deer, elk, moose, and bears, and is often evidence that the animal’s immune system is not functioning properly. Psoroptic scabies, caused by mites of the genus Psoroptes, have been known to infect bighorn sheep, causing severe inflammation and damage to the ear canal and sometimes hair loss on the head and neck.

Distribution

Various mites that can cause mange are found nearly worldwide. In Montana, sarcoptic mange is the most common type of mange observed in wildlife, usually infecting wolves, foxes and coyotes. Infections are observed throughout the year but most observed during winter months when hair loss can be life threatening (Western, 2009).

Species affected

There are several species of Sarcoptes, and although different species of the mite seem to have some host preference, they can sometimes infect other hosts. Sarcoptic mange has been reported in a wide range of mammals nationwide. The disease is commonly found on red fox, wolves, and coyotes in North America. Cats, bears, porcupine, rabbit, raccoon, squirrels, and mustelids may also become infected. Mange in wild species predominantly affects younger animals (Western, 2009)Sarcoptes scabiei (the sarcoptes of canids) can infect humans, although in most cases the infection is self-limiting. Humans have their own species of sarcoptes mite that is transmissible from human to human. There are some elk populations in Montana in which manage due to Psoroptes infection has been documented and disease occurs at varying degrees. In some cases, the combination of hair loss and winter weather results in elk mortality. Psoroptes has also been documented in a bighorn lamb that was capture in 2018. 

Transmission

Mange is highly contagious between hosts of the same species. Transmission usually occurs by direct contact with an infected animal, or from a contaminated environment (bedding areas, dens, etc.). Mites can remain infective without a host for extended periods; an important factor in the maintenance of the disease (Miller et al, 2003Western, 2009).

Signs

Sarcoptic mange is characterized by intense itching. Hair loss, reddening of the skin, and damage to the surface of the skin usually begin to develop on the ventral abdomen, chest, ears, elbows, and hocks. As the condition progresses, skin lesions become more generalized, affecting more and more of the body. Secondary bacterial and yeast infections are common complicating factors. In severe cases, there will be thickening of the skin, with dark pigmentation and the development of crusts. Affected skin is itchy and self-trauma may often be evident. Badly affected animals may be in poor body condition, weak, and fearless, and carnivores may scavenge with increased frequency. Those that are severely affected may ultimately die from complications with mange infection or exposure to the elements (winter weather) (Miller et al, 2003). The disease seems particularly pathologic to foxes, especially among kits in the summer. Skin changes around the eyes, ears and mouth may cause blindness, impaired hearing, and difficulty in eating (Michigan, 2010).

Demodectic mange has been detected sporadically in deer, elk and moose. Often, these animals have a compromised immune system, and may have other underlying health problems. They are commonly in poor condition. Hair loss tends to be bilateral (similar pattern on both the left and right), and may affect the head/neck, flank, hindquarters, or much of the body. Hair loss in these animals may contribute to weight loss because the animal will have to use more energy to stay warm. Mange in cervids must be differentiated from winter tick infestation, lice infestation, and normal hair loss from molting.

Psoroptes infection in bighorn sheep can cause severe inflammation and damage to the ear canal and inner ear of affected sheep. The ear may be very swollen and thickened, and contain a large amount of debris, and there may be thick crusts on the inner surfaces of the ear. Sheep may become deaf as a result and be at higher risk of predation. Sometimes the lesions will go beyond the ear to cause hair loss and crusting of the skin of the head and neck. Affected bighorn may have droopy ears and may be seen shaking their head. Psoroptes has also been documented in elk in Montana. It can cause varying degrees of hair loss, and in servere cases animals may become emaciated and die. 

Public Health Concerns

Sarcoptic mange mites are known to transfer from animal hosts to people, but the risk appears to be low (Stitt, 2011). Lesions usually occur at sites where contact was made with infected animals. Skin becomes red, inflamed and intensely itchy. Human infections from animal sources are short-lived and self-limiting (Miller et al, 2003). Precautions should be taken when handling an animal that may have mange. Wear gloves and long sleeves, wash hands with warm soapy water afterwards, and disinfect workspace after skinning/ handling potentially infected animals (Stitt, 2011).

Is it safe to eat the meat?

Mange mites alone do not affect meat quality or safety; however, some animals with severe infections may develop secondary bacterial infections that do have potential to affect the quality of the meat. Some clues that the meat may not be fit for human consumption are:

  1. animal is in poor body condition
  2. animal has a foul odor
  3. animal has enlarged lymph nodes
  4. unusual color or consistency of the meat.

If you harvest an animal and are unsure whether it is safe to eat, contact your local FWP staff for guidance soon after the animal is harvested.

Citations

Michigan Wildlife Disease Manual. 2010. Michigan Department of Natural Resources.Website

Miller, M.J.R., R.D. Dawson, and H. Schwantje. 2003. Manual of Common Diseases and Parasites of Wildlife in Northern British Columbia. University of Northern British Columbia.

Stitt, Tyler. 2011. Diseases You Can Get From Wildlife - A Field-guide for Hunters, Trappers, Anglers and Biologists. British Columbia Ministry of the Environment.

Western Wildlife Disease Workshop Notebook. 2009. Southeastern Cooperative Wildlife Disease Study. College of Veterinary Medicine, University of Georgia.