Mange is a skin disease of domestic dogs caused by one of several different species of parasitic mites. The mites that most commonly affect dogs are: Sarcoptes scabiei, which causes sarcoptic mange ("canine scabies"); Cheyletiella yasguri, which causes cheyletiellosis ("walking dandruff"); and Demodex canis, which causes demodicosis ("demodex").
Causes & Prevention
How Mange Affects Dogs
Sarcoptes mites cause a non-seasonal, highly contagious and intensely itchy skin condition in dogs of all breeds, with no age or gender predisposition. People can be infected as well. These mites burrow through several skin layers and release a highly irritating substance that causes severe itchiness, scratching, hair loss and self-trauma, especially on the outside of the ears, elbows, back of the hind legs, on the chest and across the groin and abdomen. As the mites multiply, the condition worsens and can contribute to depression, aggression, lack of interest in play, inappetence, weight loss, significant hair loss and other physical and behavioral changes.
Cheyletiellosis, which also is highly contagious, causes marked skin scaling, which normally is most apparent on the dog's back but can appear anywhere. It may or may not be accompanied by itchiness, but unlike the Sarcoptes mites, these mites do not cause deep and excessive underlying skin irritation. These large mites can easily be seen with a simple hand-held magnifying glass. People are subject to infection as well.
Demodicosis typically does not cause itching. Its most obvious clinical sign is patchy hair loss, which can be localized or generalized. The patches tend to occur on the face, especially around the eyes and mouth, in localized cases. Affected areas of skin often become oily, moderately scaly, crusty and thickened. Secondary bacterial skin infections are quite common as the mites multiply in hair follicles.
Causes of Canine Mange
Sarcoptic mange is caused by the Sarcoptes scabiei mite, and Cheyletiellosis is caused by the Cheyletiella yasguri mite. Both of these conditions are highly contagious; common sources of infestation are boarding kennels, animal shelters, dog parks, grooming facilities and other high-density dog-friendly areas. Demodectic mange is caused by the Demodex canis mite, which is a normal inhabitant of hair follicles and sebaceous glands in dogs. Clinical disease develops when the mite population proliferates beyond what the animal's immune system can handle. A genetic component has been suggested.
Preventing Mange in Dogs
The best way to prevent mange is to avoid direct contact with affected animals. Because demodex is thought to have a heritable component, dogs with the generalized form of this condition should not be bred.
Sarcoptic mange, and to a lesser degree Cheletiellosis, are zoonotic, meaning that people can become infected. Dogs with mange should be treated with the appropriate medicated shampoos and topical dips. In the case of sarcoptic mange and cheyletiellosis, all animals in the home should be treated and the home should be professionally treated for mite infestation. The prognosis for dogs with mange is generally good as long as treatment protocols are rigorously followed.
Symptoms & Signs
"Mange" is a general term that actually refers to several different skin disorders caused by several different species of parasitic mites. The Sarcoptes scabei mites cause a nonseasonal, highly contagious and intensly pruritic (itchy) condition in dogs of all breeds, with no age or gender predisposition. Humans can be infected as well. These mites burrow through several layers of skin and not only mechanically irritate affected animals, but also produce irritating allergic substances that exacerbate the hypersensitivity (allergic) reaction. If left untreated, secondary bacterial infections often accompany mite infestation. If your dog suddenly shows signs of intense itching, schedule an appointment with your veterinarian as soon as possible. Timely treatment will stop the spread of these nasty parasites to other animals in the household, and your dog will be relieved of the pain, and intense itching, that they cause.
Symptoms of Mange
Clinical signs of "mange" caused by Sarcoptes scabei mites almost always include severe itching, scratching and hair loss. Ironically, these mites prefer areas of the skin where there is minimal hair, so the itching and scratching often are most intense on the ears, elbows, under the "arms," on the back of the hind legs, on the hocks, chest and across the groin and belly area. As the mites multiply, and the dog continues to scratch, the skin will become red, inflamed, infected and sore.
Untreated mange can lead to severe skin infections due to the scratching and accompanying allergic reaction to the mites. Red bumps full of puss (called "pustules") can appear on the skin, which also may darken, thicken and develop a leathery appearance. Self-inflicted wounds caused by scratching are especially prone to developing secondary bacterial infections.
Prolonged infection by the Sarcoptes scabei mite can lead to depression, aggression, lack of interest in activities or play, reduced appetite, weight loss and a number of other physical and behavioral changes. The skin of infected dogs can become dry, cracked and brittle, and hair in affected areas can fall out. In extremely severe cases, the dog's skin can actually slough off in small pieces, which obviously is very distressing to owners.
If your pet has been diagnosed with sarcoptic mange, it is important for you to follow the treatment plan recommended by your veterinarian. Because this type of mange is highly contagious, all pets in the household should be treated even if they are not showing clinical signs of infection.
There are several different species of parasitic mites that cause what is commonly referred to as "mange" in dogs. The classic canine mange is caused by Sarcoptes scabiei mites, which burrow into the deep layers of a dog's skin and cause severe itching and allergic irritation. Called "scabies" or "sarcoptic mange," this condition is highly contagious to other dogs, and to people as well.
If your pet is diagnosed with sarcoptic mange, you should follow the treatment plan prescribed by your veterinarian. A missed dose or an incomplete treatment protocol can lead to re-infestation. The dog's environment should be treated as well. All animals that are in contact with an infected dog also must be treated, whether or not they show clinical signs of disease.
Sarcoptic mange is best treated by medicated dips, shampoos and other prescription topical therapies. Oral medication is available as well. Medicated dips and other topical therapies must be administered regularly; it can take 4 to 6 weeks for the clinical signs of mange to resolve, even with regular treatment. Some breeds, especially Collies and Shelties, are intolerant to ivermectin, which is one of the medications often used to treat mange. These breeds need special attention to their treatment protocols. Sometimes, mange can involve secondary bacterial infections. In these cases, a veterinarian may prescribe antibiotics, anti-inflammatories and/or pain medication.
"Old-time" remedies to treat mange are ineffective and can actually exacerbate damage to the dog's skin. Some of these so-called "remedies" include rubbing motor oil or vegetable oil into the dog's skin, lightly applying gasoline onto the dog's coat or repeatedly bathing the dog. None of these "remedies" even physically touch the mites, as they live deep beneath the surface of the skin. Motor oil and gasoline cause skin irritation, infection and can endanger a dog's health; vegetable oil and repeated bathing can exacerbate skin irritation as well. If your dog suddenly starts scratching intensely, please make an appointment with your veterinarian rather than trying one of these ineffective "treatments."