Red mange in dogs

Red mange or demodectic mange or demodicosis is caused by mites of the genus Demodex. The most common of these mites found on dogs is Demodex canis although dogs also carry Demodex gatoi and Demodex injai. All dogs carry some Demodex mites catching them from their mothers during the first few days of life.

While all dogs carry Demodex mites, not all dogs develop demodicosis. The development of this type of mange depends on the immune status of the dog and its genetics.

Unlike sarcoptic mange, demodectic mange is non-itchy although bacterial super-infections occasionally cause the dog irritation.

Humans also develop demodicosis but the mites infecting humans are not the same species as those found on dogs. Therefore you cannot catch this from your dog.

Localized demodicosis, where a couple of areas of reddened skin and hair loss appear on the dog, is quite a common condition in puppies and young dogs. Normally as the immune system of the dog matures, the condition clears spontaneously. This form of demodicosis commonly affects the head of the dog. Localized demodicosis only affects a maximum of two body parts and in localized demodicosis produces no more than four separate areas of reddened skin are present. As it usually clears spontaneously and causes little or no irritation, localized demodicosis requires no treatment.

Some young dogs under a year and a half in age develop generalized demodicosis. In this, the dog may develop many areas of reddened hairless skin giving it a polka dotted appearance or the whole of the dog’s body may be affected resulting in a hairless red dog. The tendency to develop this form of form of demodicosis in a young dog is a genetic trait and such dogs must not be used for breeding.

Generalized demodicosis developing in older dogs may indicate an underlining condition affecting their immune system. Such dogs require thorough veterinary examination to find the underlying cause of their condition. Cancer, liver disease, hormonal imbalance and kidney disease can precipitate generalized demodicosis in older dogs.

A condition known as Demodectic Pododermatitis affects only the paws of the dog. Particularly common in Old English Sheepdogs and Shar Peis, this leads to reddened hairless toes. It sometimes represents the last area of infestation after treatment of a dog with generalized demodicosis. The mites causing this form are deep in the hair follicles causing it to be the most difficult form to treat.

The FDA approved treatment of generalized demodicosis requires whole-dog dipping in 0.025% Amitraz at two week intervals. This is combined with clipping the hair of the dog and shampooing with benzoyl peroxide shampoo prior to dipping. Cure rates increase when the interval between dips is cut to weekly and a 0.05% or 0.1% solution is used.

Ivermectin provides an alternative to dipping but some dogs are prone to developing severe neurological side effects with this medication. Collies, collie crosses and some other herding breeds are particularly at risk of this side effect.

Another oral medication effective for treatment of red mange comes in the form of the heartworm medication Milbemycin oxide (Interceptor). This is an expensive option but in dogs such as collies may provide an alternative to dipping.

Veterinary assistance should be sort prior to treating a dog for any from of mange to ensure correct treatment.

Finally prior to the introduction of current treatments dogs with demodicosis were dipped in motor oil. On no account should this treatment ever be used. Such treatment is toxic resulting in damage to the dog’s liver and kidneys as well as sometimes causing pneumonia.

Reference sources:

Mar Vista Animal Medical Center

Merck Veterinary Manual