Mange in Wildlife

Microscope view of mange mite
Microscopic view of a mange mite.

Mange is an emerging wildlife disease and the focus of many studies. In recent years, some particular types of mange have been reported in new geographic areas, in increasing numbers. During the past decade, several East Coast states, particularly Virginia and Pennsylvania, have reported an increase in bears with mange. Biologists and researchers are working toward learning more about this disease.

Each year, the Wildlife Center admits, treats, and answers questions about dozens of wild animals affected by mange. Learn more about this issue and how you can help.

What is mange?

Mange is a contagious skin disease caused by mites. There are a few different types of mange, each caused by a different mite species.

  • Sarcoptic mange, caused by the Sarcoptes scabiei mite, is the most common. These mites burrow into the outer layer of an animal’s skin and form tunnels. Female mites lay eggs within the tunnels; within three days, larvae hatch and either move in the tunnels, or move to the surface of the infected animal’s skin. Within days to weeks, the larvae develop into nymphs, which then develop into adult mites – ready to repeat the cycle. Mange treatment can be challenging since larvae, nymphs, and adults can all be living on the same host in different life stages.
  • Demodectic mange, caused by Demodex mites, is less commonly seen in wildlife but is often seen in dogs. This species of mite inhabits hair follicles and can be regularly found on animals. In a healthy animal, low numbers of these mites cause no symptoms and are simply a regular part of normal skin microfauna. In immunocompromised animals, the mites quickly multiply and can cause hair loss and severe illness.
  • Audycoptic mange, caused by the Ursicoptes americanus mite, is a bear-specific mange. This disease is similar to sarcoptic mange, but only affects bears. Secondary skin infections typically aren’t quite as severe as in sarcoptic mange cases.
Dead fox with mange
Fox deceased from mange infection.

What animals are affected?

Mange affects a variety of mammals—most notably foxes and other canids, bears, coyotes, rabbits, squirrels, and raccoons.  Sarcoptic mange can also affect humans, making it a zoonotic disease, though different subspecies of the S. scabiei mites are often adapted to specific hosts, which makes some infections self-limiting. A specific variety of the S. scabiei mite causes scabies in people. 

How is mange spread?

Mites are transferred to new hosts when the affected animal comes into direct physical contact with others. Larvae and nymphs may also fall off the host animal and can survive in the environment for several weeks. If an uninfected animal encounters a contaminated environment (e.g., moving into a shared nest or den), the mites can infect the new animal.

It’s important to note that some animals are exposed to mange mites and do not show any signs of infection; why certain animals are more affected is a subject of current research. Factors include host species, mite variety, and general host health and immunity.

What are the symptoms of mange?

Animals affected by sarcoptic mange often exhibit intense itchiness, hair thinning and loss, thickened skin, and scabbing. Hair loss is typically most pronounced around the animal’s face and ears. The infected animal may also develop a secondary bacterial skin infection, noted by additional foul-smelling crusts.

Severely affected animals will become thin, depressed, and lethargic. Although affected animals are usually physically capable of eating, they often cannot consume enough calories to support themselves nutritionally while also trying to fight off the disease. Some animals will develop compromised sight/hearing due to the severity of crusting around the ears/eyes.

Mange fur loss
Mange fur regrowth

Animals infected with demodectic mange also experience hair loss with dry, thickened skin. Because affected animals are typically those that are already immunocompromised, animals are also typically in poor body condition.

How is mange diagnosed?

Mange can’t be diagnosed by symptoms only; there can be several causes of hair loss in animals, including ringworm, bacteria, other parasites, or even routine shedding.

A definitive diagnosis is made by examining samples from skin scrapings under a microscope to look for mange mites. Typically, multiple skin scrapes are needed since mites may be in different life stages on different parts of the body.

Animals with mange also usually need additional diagnostics to confirm secondary bacterial infections.

Can mange be treated?

Depending on the species, mange may be able to be successfully treated by administering medication that kills the mites. The successful treatment of mange is currently a significant focus of research; biologists, veterinarians, and other wildlife professionals are exploring new medications that can be used more effectively to treat affected wildlife.

A fox before and after its mange treatment. The fox is pictured with missing hair and crusty skin in a live trap on December 1. On February 2, he has a full coat of red hair.

Typical treatment includes administering an oral or injectable anti-parasitic drug to the animal; sometimes antibiotics and anti-inflammatories are also prescribed to treat secondary infections in severely affected animals. Severely affected animals may not survive despite treatment; while the mites may be killed with the medication, the animal’s body condition and overall health may be too compromised for recovery.

It’s important to note that each affected animal needs to be individually treated based on body weight and other factors; it’s not safe (or legal) to attempt to leave medicated food for an animal in an outdoor environment. While it may be tempting to leave medication-laced food for an affected animal, there is often no guarantee that the correct animal will receive the medications.

The Center’s Research on Bear Mange

In 2017, Dr. Peach Van Wick, the Center’s veterinary research fellow, began a two-year experimental trial on a new drug for treating bear mange. The focus of this study was to determine if a one-time treatment for bear mange was both safe and successful, which could have significant implications for how the treatment is deployed—that is, allowing biologists to medicate affected bears in the field, rather than needing to capture and transport bears to a wildlife hospital for treatment.

Read the abstract “Treatment of Sarcoptic Mange in an American Black Bear (Ursus americanus) with a Single Oral Dose of Fluralaner”.

Unfortunately, while the medication was effective, and treated bears regrew their hair and resolved their skin abnormalities, post-release tracking data indicated that the majority of these bears were re-infested with mange within one year of their release, with even more significant mange infestations.

A before-and-after comparison of an adult black bear. The top photo shows a bear laying asleep on a stretcher missing a significant portion of hair; the bottom photo shows a fully furred bear laying on a blue stretcher.

The emergence and spread of bear mange remains a significant area of research for state agencies, researchers, biologists, and other collaborators like the Wildlife Center. Understanding genetics, immune health, and other factors are all goals for those working on this issue.

 What You Can Do

  • Don't feed wild mammals. The artificial congregation of wild mammals can help the transmission of mange mites to new hosts and contribute to the spread of this disease.
  • In Virginia, report any potential bear mange cases to the Department of Wildlife Resources' Virginia Wildlife Conflict Helpline at vawildlifeconflict@usda.gov or 1-855-571-9003. Include the exact location and a photo if possible; DWR tracks reported cases to learn more about the spread of bear mange.
  • If you find a suspected mangey wild animal in need of help, call your local permitted wildlife rehabilitator or veterinarian for advice and instruction.