How to Spot Mange in Dogs
While mangy is a term used to describe animals that are in poor health, mange is a type of skin disease in dogs caused by a variety of parasites. There are numerous ectoparasites that can cause skin disease in dogs, but mange typically refers to two major mite species: Demodex and Sarcoptes spp.
Demodectic Mites
Demodicosis (aka demodectic mange or red mange) is caused by various species of Demodex mites. Demodex mites are species specific, meaning that they are not contagious between other dogs or between dogs and humans.
There are two main species of Demodex:
- Demodex canis, which is a follicular mite.
- Demodex injai, which is more superficial and affects the sebaceous glands.
Classifications of Demodectic Mange
Demodex mites are considered a normal part of the fauna of the skin, meaning that all dogs have them, but only certain dogs will have abnormal proliferation.
There are several classifications of demodectic mange:
- Localized demodicosis is most commonly seen in young dogs and results in several (6 or less) small areas of hair loss that are inflamed, but not generally itchy. These lesions are most common on the face and limbs, and will resolve spontaneously and rarely need treatment.
- Generalized demodicosis results in more than six lesions that affect an entire body region, such as the face, ear canals, or paws.
- Juvenile demodicosis typically occurs in dogs under two years of age. Symptoms may include: hair loss, comedones (black heads), scaling, pododermatitis (inflammation of the paws), otitis (inflammation of the ears), lymphadenopathy (enlarged lymph nodes), folliculitis (inflammation of the hair follicles), furunculosis (rupture of the hair follicles), and crusting. Pruritus (itch) is generally only present if secondary infection is present.
- Adult onset demodicosis has the same clinical signs as the juvenile strain, but occurs in dogs older than 2 years of age with no history of juvenile demodicosis. This condition can be a sign of underlying illnesses like hypothyroidism, Cushing’s Disease, or cancer. Older dogs diagnosed with demodicosis will generally need a more complete work up by a veterinarian.
In order to diagnose Demodex mites, your veterinarian will need to perform a deep skin scrape. These mites are microscopic, so you won’t be able to see them with the naked eye. There are several treatment options, many of which include the antiparasitic drugs used for flea and tick prevention. The best option will be based on the overall health and breed of your dog.
Canine Scabies
Canine scabies (aka sarcoptic mange) is a non-seasonal skin condition caused by microscopic mites, scientifically known as Sarcoptes scabiei var. canis. These mites are typically picked up from other infected dogs or cats (in boarding or grooming environments and dog parks), from direct contact with wildlife carriers (coyotes, foxes), or infected outdoor environments. Sarcoptes mites can be contagious to other animals in the household and are zoonotic, meaning that they can affect humans as well.
Common clinical signs associated with sarcoptic mange are an intense and unrelenting itch. The most commonly affected areas of skin are the ears, ventral abdomen, hocks, elbows, and feet. Common lesions include crusting, red bumps, hair loss, and often signs associated with self trauma, like bleeding and crusting.
Usually, the itching and lesions begin 3-4 weeks after exposure. Dogs with sarcoptic mange often are non- or less responsive to therapies directed at controlling itch. Diagnosis requires skin scrapes to uncover these mites, although they are much harder to find than the Demodex variety. In some cases, if clinical suspicion is high, a veterinarian may suggest trial treatment, though itch level may spike even after treatment is initiated. There are many treatment options for sarcoptic mange, which are similar to the medications used to treat fleas and ticks.
Ultimately, most cases of true “mange” are very treatable. However, there are many other skin diseases that mimic the appearance of mange, such as food and environmental allergies. A full work up with skin scrapes is always recommended if you suspect your dog suffers from mange.