Sarcoptic Mange

Sarcoptic mange or Canine Scabies is a highly contagious, parasitic skin disease of dogs. It is a non-seasonal disorder caused by infestation of sarcoptic mange mites. The mites burrow through the upper surface of the skin and cause intense itching and irritation. The mites secrete substances (allergens) that produce an allergic or hypersensitivity reaction in some dogs.

What causes sarcoptic mange?

Sarcoptic mange is caused by infestation of the mite, Sarcoptes scabiei. Sarcoptic mange is a contagious disease – the infestation follows exposure to another dog with sarcoptic mange. Roaming dogs and dogs living outside are potential carriers of the disease. The dog can be exposed to sarcoptic mange mites at shelters or kennels and during visits to grooming facilities or veterinary offices. Foxes and wombats are also potential sources of infection.

The sarcoptic mange mite can cause skin problems in human family members that come into contact with a dog infested with Sarcoptes. People who come in close contact with an affected dog may develop an itchy rash with small raised bumps (papules) on their arms, chest, or abdomen. Rashes in people usually are temporary and should resolve after the affected dog has been treated. Any affected person should contact a physician regarding possible treatment.

What are the signs of sarcoptic mange?

Sarcoptic mange is a very itchy condition. The pet will have hair loss and a red rash. The signs generally are seen on the elbows, hocks, abdomen, and chest. Scaling and crusting may be present on the ears. Rubbing the ears will cause the dog to scratch with its hind leg. The dog will scratch, leading to sores on the skin and pus-filled lesions may develop. Occasionally, the lymph nodes will enlarge.

How is sarcoptic mange diagnosed?

Sarcoptic mange is diagnosed primarily upon history of exposure to other dogs or foxes (generally two-to-six weeks before the skin problems) and physical examination. The veterinarian will want to differentiate sarcoptic mange from other conditions with similar signs, such as food or flea allergies. Examination of skin scrapings may be attempted to identify the mange mite, but false negative results are common. Examination of the stool may reveal mites or eggs.

Since it frequently is difficult to find the mange mites on the dog, the pet will be treated for sarcoptic mange based on the veterinarian’s suspicion. If the dog’s signs resolve following treatment for sarcoptic mange, the diagnosis is made based on the dog’s response to treatment.

How is sarcoptic mange treated?

Sarcoptic mange is treated by killing the mange mites on the dog. Clipping the dog is recommended, followed by repeated applications of specialised shampoos and antiparasitic dips or administration of antiparasitic compounds by mouth. More recently, topical ‘spot-on’ treatments have been registered for the treatment and control of sarcoptic mange. Baths and dips usually are done once weekly and continued for two weeks beyond remission of signs. When dips are used, the entire dog must be dipped, including the dog’s face and ears, and the dog cannot be allowed to get wet between treatments. Spot-ons are applied monthly.

Your veterinarian is the best person to advise which treatment is suitable for each individual case. Instructions for use of these products should be followed carefully. Other medications may be prescribed; some dogs benefit from corticosteroids. Antibiotics may be needed if the skin lesions contain pus, indicating possible infection. In homes with several dogs, all dogs should be treated, even those with no signs because they may be carriers; and it can take one month for signs to develop.

What is the prognosis for dogs with sarcoptic mange?

With proper treatment, the outcome for dogs with sarcoptic mange is good. Response to treatment should be seen within two weeks, although treatment will need to be continued for two weeks beyond remission of signs. Prevention of sarcoptic mange in at risk dogs can be achieved using monthly ‘spot-on’ treatments.

Dr Julia Adams BVSc

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