Red Fox Mange
Prince Edward Island is known for its population of urban red foxes. In the city of Charlottetown in particular, red foxes are a common sight and can often be observed sauntering down the street, seemingly unperturbed by pedestrians or vehicles. This winter however, an outbreak of mange has descended upon Charlottetown’s foxes, and in many their beautiful red pelage has been replaced by a sparse and patchy coat, interspersed by expanses of crusty grey, hairless skin. Mange in red foxes is caused by a burrowing mite, Sarcoptes scabiei, which infests the skin of many species of canids including red foxes, coyotes, wolves, and domestic dogs. The mites burrow through the superficial layers of the epidermis (outer layer of the skin) where they lay their eggs. The eggs hatch and spend their entire lives on a single host. The burrowing mites and their biological products are extremely irritating to the host and result in hypersensitivity reactions that cause inflammation and pruritus (itching). The resultant scratching causes significant trauma to the skin which develops thick grey, foul smelling crusts with extensive hair loss. The extreme discomfort and hair loss caused by this disease over weeks to months leads to the death of the animal due to a combination of starvation and exposure to the elements (particularly in the winter). The mites are transmitted between hosts by direct skin to skin contact. They typically do not survive long in the environment, although they may persist for weeks in dens and bedding if the conditions are right. Mange is fairly common in wild canids on the mainland, but to our knowledge, this is the first outbreak of mange in red foxes we have seen on PEI. A small outbreak of mange occurred in PEI coyotes in the early 90’s, however, nothing has been officially documented since then. Mange typically persists at low levels in wild populations, but outbreaks may occur with high density populations which promote increased contact between individuals. Although mange may cause significant mortality, it does not have long lasting effects on populations which can fully recover with time. The CWHC is working closing with the Department of PEI Fish and Wildlife to monitor the spread of mange in PEI foxes.
It is important to remember that fox mange is readily contracted by pet dogs. In dogs, the first signs of disease are severe itchiness and reddened skin which progresses to marked crusting as described in foxes. If an owner suspects their dog may have mange, they should contact their veterinarian immediately who can prescribe appropriate treatment. Humans in close contact with foxes may also contract mange, however, in healthy individuals this tends to be a mild, transient infection that resolves on its own. In individuals with a compromised immune system, infection may be prolonged and difficult to treat. Any person concerned they may have contracted mange should consult a medical doctor immediately.
Contributed by Laura Bourque, Veterinary Pathologist CWHC-Atlantic
For more information read our sarcoptic mange fact sheet HERE.