Mange in dogs: Symptoms and treatment

AbbyMac By AbbyMac, 11th Jul 2010 | Follow this author | RSS Feed
Posted in Wikinut>Guides>Pets>Dogs

If your dog begins to show signs of patchy fur and excessive itching the culprit could be mange. Canine mange is a general term used for several skin conditions in dogs caused by mites: sarcoptic mange and demodectic mange.

Sarcoptic Mange

Description and Symptoms

Sarcoptic mange, also called scabies, is caused by the Sarcoptes scabiei mite. The female mite burrows under the skin to lay her eggs, causing intense itching. The eggs hatch, mature and lay their own eggs creating a cycle of increasing discomfort for the dog. Common sites affected are the face, ears and elbows. The dog will chew and scratch the area for relief. The constant scratching leads to hair loss and a thickening of the skin. Another symptom is head shaking and tender, crusty or swollen ear tips. If left untreated scabbing and pyoderma, a bacterial skin inflammation of pus-filled lesions, develops that also must be treated.

Scabies is highly contagious to other mammals including humans. The mite cannot complete its life cycle on humans so an infestation will resolve itself in about three weeks. However, a dog must be treated.

Diagnosis and Treatment

Diagnosis of sarcoptic mange can be made by microscopically examining a skin scraping of the affected area. In more advanced stages where a secondary infection has begun the results will be masked so diagnosis is based on the dog's history and symptoms.

Mange treatment is accomplished with an oral or injectable form of Ivermectin, given in several doses. This is an off-label use of this drug, but it has been safely administered to dogs for mange. Collies, shelties and other herding breeds can be sensitive to Ivermectin so a different miticide, such as Paramite, is used with those breeds. All animals in the home need to be treated even if they are asymptomatic. Scabies is highly contagious so it should be assumed everybody has it.

Steroids, such as cortisone, are used to ease the inflammation and itching. If the dog has a secondary bacterial infection it can be treated with topical antibiotics. It is this bacterial infection that will take the longest to heal.

Demodectic Mange

Description and Symptoms

Demodectic mange, also known as demodicosis or red mange, is caused by the mite Demodex canis. This mite is found in almost all puppies and is passed from the mother to the puppy during the first week of life through direct contact only. The mite cannot live off the dog so the environment, such as bedding, will not spread it. The puppy's immune system is usually strong enough to keep the number of mites in check, thereby never developing mange. A compromised immune system, possibly because of stress, can allow the mite to multiply in sufficient numbers to cause symptoms.

Symptoms are mild and not usually itchy. Several small crusty patches of hair loss may appear around the eyes or muzzle of the puppy. This only occurs after 3 months of age and in most cases will resolve itself before 14 months. There seems to be a hereditary component to the susceptibility of a demodex outbreak. Short-haired oily breeds are more vulnerable, probably due to the mite's preference to living in the hair follicle, creating clogged, gunky pores.

If this relatively harmless localized form becomes more generalized it is much more serious requiring immediate treatment. Hair thinning will occur in patches all over the body with sores, oozing and possible infection.

It is unusual for an adult dog to get demodectic mange. If he does, it is a sign that his immunity is compromised and he should be checked for underlying conditions that lead to a suppressed immune system.

Humans cannot catch Demodex canis; they have their own mite, Demodex folliculorum. These mites are species specific so there is no risk of cross contagion.

Diagnosis and Treatment

The localized form of demodectic mange is easily handled by most puppies' healthy immune systems and does not need treatment. Shampoos and dips may help to relieve some symptoms if they are bothersome.

The generalized form is diagnosed microscopically with a skin scraping or biopsy. The organophosphate dip Amitraz (Mitaban) is used repeatedly over a length of time to reduce the number of mites. This is a powerful insecticide so gloves should be worn at all times when touching it. Some toy breeds are sensitive to this treatment and should have a half-strength dip. If the Amitraz does not work the mange can also be treated with Ivermectin, similar to the scabies treatment.

Antibiotics will be given to treat secondary bacterial infections and steroids can be given if the dog is excessively itchy. Treatment will take a long time and the condition can recur. A dog is not considered free of generalized demodicosis until he has been free of the mite for one year.

Tags

Canine, Demodectic, Demodex, Demodicosis, Dog, Mange, Sarcoptic, Symptom, Treatment

Meet the author

author avatar AbbyMac
I am a mother of two teenage girls, living on a farm where we raise award-winning Corriedale Sheep. I have homeschooled for 11 years and currently own a homeschool curriculum store. I enjoy writing about homeschooling, animals and mysteries of the ...(more)

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