Mange in Dogs (Canine Scabies)
Mange is a skin disease caused by several species of tiny mites, common external parasites found in companion canines. Some mange mites are normal residents of your dog’s skin and hair follicles, while others are not. All mites can cause mild to severe skin infections if they proliferate.
What Causes Mange in Dogs?
Sarcoptic mange (Sarcoptes scabei) is transferred easily between hosts. Also known as canine scabies, sarcoptic mange is caused by mites that are oval-shaped, light-colored and microscopic.
All dogs raised normally by their mothers possess demodectic mange mites (Demodex canis), which are transferred from mother to pup via cuddling during the first few days of life. Most dogs live in harmony with their mites, never suffering any consequences.
There are three types of demodectic mange that affect canines. Localized cases occur when these mites proliferate in one or two small, confined areas. This results in isolated scaly bald patches-usually on the dog's face-creating a polka-dot appearance. Localized demodicosis is considered a common ailment of puppyhood, and approximately 90% of cases resolve with no treatment of any kind.
Generalized demodectic mange, in contrast, affects larger areas of skin or a dog’s entire body. Secondary bacterial infections make this a very itchy and often smelly skin disease. This form of mange could also be a sign of a compromised immune system, hereditary problem, endocrine problem or other underlying health issue. Treatment depends on the age at which the dog developed the disease.
One of the most resistant forms of mange, demodectic pododermatitis is confined to the foot and accompanied by bacterial infections. Deep biopsies are often required to locate these mites and make a proper diagnosis.
Is Demodectic Mange Contagious?
Current thinking is that Demodex mites can be transferred from one dog to another-but as long as the dog is healthy, the mites simply add to the dog's natural mite population and no skin disease results. Isolation of dogs with even the most severe cases is still felt to be unnecessary-though in rare circumstances, contagion is possible. While there are still different theories about dog-to-dog transmission of Demodex mites, it is accepted that mites cannot be transmitted to humans or to cats.
What Are the General Symptoms of Mange in Dogs?
The symptoms of mange depend on which type of mite is present. Demodectic mange tends to cause hair loss, bald spots, scabbing and sores. Secondary bacterial infections can make demodectic mange an itchy and uncomfortable disease.
Sarcoptic mange tends to cause intense itching. It can result in restlessness and frantic scratching, symptoms that generally appear one week after exposure. It also can result in hair loss, reddened skin, body sores and scabs. The most commonly affected areas are a dog’s ears, elbows, face and legs, but it can rapidly spread to the entire body.
When passed to humans, sarcoptic mange causes a rash of red bumps, similar to mosquito bites. Humans cannot get demodectic mange from dogs.