Sarcoptic Mange

What is mange?

Mange is a parasitic skin disease caused by microscopic mites. Three different types of mites can commonly cause problems in dogs:-

The otodectic mite usually infests the ears resulting in otodectic mange. This causes irritation leading to bacterial infection which can result in otitis externa.

The demodectic mite usually resides in the hair follicles of the skin, and can cause demodectic mange.   This is the most common form of mange in dogs. 

The sarcoptic mite is responsible for canine scabies (sarcoptic mange). It lives just under the skin.

This client handout concentrates on sarcoptic mange, also known as scabies, particularly when it is transmitted to us since it is zoonotic. Separate handouts deal with demodectic mange and otodectic mange.

What is the cause of sarcoptic mange?

Sarcoptic mange, also known as scabies or fox mange, is caused by a slightly larger mite than that causing demodectic mange. The sarcoptic mange mites live permanently within the top layers of the skin on which it feeds, creating burrows in which it lays its eggs. 

What are the clinical signs?

Sarcoptic mange is considerably more irritant to the dog than demodex due to a hypersensitivity reaction to the secretions produced by the mite. Affected dogs chew and scratch constantly, often causing considerable skin damage which can lead to a secondary infection (pyoderma). Ear tips, elbows and hocks are the areas most frequently affected initially but untreated the condition can affect the entire body surface. The skin ultimately becomes thickened and darkens due to pigmentation. The condition is debilitating. Weight loss and listlessness often develop at the same time as secondary skin infection. The condition is frequently seen in young dogs particularly if neglected but any age group is susceptible.

"Affected dogs chew and scratch constantly, often causing considerable skin damage which can lead to a secondary infection (pyoderma). Ear tips, elbows and hocks are the areas most frequently affected initially but untreated the condition can affect the entire body surface."

Is it contagious?

Sarcoptic mange is very contagious to other dogs and also is communicable to man (zoonotic).

What are the symptoms when people are affected?

Owners, particularly children, living with an affected dog, often develop scabies. The signs are usually small, red, circular areas on the skin particularly the arms and abdomen. These lesions are intensely itchy. If you have a dog with confirmed sarcoptic mange and develop any lesions yourself, contact your doctor without delay. The condition is not as serious in people as in dogs and usually clears up quickly with topical applications prescribed by your doctor. In man the mite is unable to reproduce as it does in the dog. Although it cannot complete its life cycle, it can still cause a great deal of irritation.

How did my dog contract mange?

Since sarcoptic mange is highly contagious it could have been contracted from contact with an affected dog or recent occupation of a space previously occupied by such a dog. It is also known as fox mange. Foxes and wombats carry large number of sarcoptic mites and if your dog has been in contact with a fox, wombat or even a place where those animals live, this is sufficient. Puppies contract the condition from their mothers at a young age particularly if their living conditions are substandard.

How is sarcoptic mange diagnosed?

A tentative diagnosis is often made on the signs and the history but positive diagnosis is usually made by examination of several skin scrapings and the demonstration of mites or their eggs. Sometimes mites cannot be detected and then definite diagnosis made on the response to treatment.   

Is it puppies that are most commonly affected?

Sarcoptic mange is probably most common in puppies but it can affect dogs of all ages which may be in part due to the increase in number of urban and suburban foxes.

Treatment

There are several insecticides which are effective against this mite and frequently the same preparations are used for treating demodex as well as intestinal parasites, e.g. worms. Depending on the severity of the condition we may also advise regular insecticidal baths. It is important that the instructions and precautions supplied with the preparations are carefully followed.

Modern insecticidal drugs usually eradicate the mites effectively but if there is secondary bacterial skin infection antibiotics and antiseptic shampoos may have to be continued for some time.

Discarding the dog’s bedding is recommended.  If this is not possible thorough disinfection will be necessary. We will be happy to advise and if necessary recommend or supply appropriate products.