How Demodectic Mange Affects Dogs
Juvenile dogs with localized demodectic mange typically are not itchy (pruritic) and do not seem to be painful. They have mild patchy hair loss that usually appears on one or only a few places on their body. However, they do not seem to suffer at all as a result of the presence of the Demodex mites. In fact, other than the cosmetic changes in their appearance, they act and appear completely normal. When dogs develop generalized demodicosis, with widespread hair loss and sores all over their bodies, they often do become itchy and painful. If this happens, they may scratch, chew or bite at their infected areas, causing self-trauma and sores (lesions) that can become secondarily contaminated and infected by bacterial or other microorganisms.
Symptoms of Demodectic Mange
Most cases of demodectic mange usually are localized, which means that the patchy hair loss (alopecia) appears only in several limited or confined areas on the dog’s body. Sometimes, the disorder becomes multifocal, meaning that there are defined areas of patchy hair loss that show up on many different areas of the dog’s body. When demodectic mange becomes generalized, it is a much more serious medical condition.
Owners of dogs with demodectic mange may notice one or more of the following signs of this condition, usually in young dogs between 3 and 6 months of age but occasionally in middle-aged to older adult dogs:
- Patchy hair loss (alopecia) anywhere on the body, but most commonly localized to the head, face (lips, muzzle, around the eyes), neck, front legs and/or shoulders. The patches of thinning hair are usually about 1 inch in diameter. This is commonly referred to as a “moth-eaten” appearance. Juvenile focal demodicosis typically resolves spontaneously within a matter of weeks to months, whether or not it is treated.
- Generalized patches of hair loss in patches that coalesce or merge to form large areas of sores and draining tracts all over the dog’s body.
- Scabbing, scaling, inflammation and crusting of the skin in one or many places
- Skin infection (redness, rawness, presence of pus)
- Plugged hair follicles
- Patchy hair loss in middle-aged to older dogs; almost always associated with some other systemic disease and/or immunosuppression
- Itchiness (pruritis) (+/-; more common with generalized demodectic mange than with the localized form)
- Scratching at affected areas
- Skin redness (erythema)
Dogs at Increased Risk
Certain domestic dog breeds are predisposed to developing demodectic mange. According to many authorities, these include the Afghan Hound, American Pit Bull Terrier, American Staffordshire Terrier, Boston Terrier, Boxer, Collie, Chihuahua, Dalmatian, Doberman Pinscher, English Bulldog, German Shepherd Dog, Great Dane, Old English Sheepdog, Pug and Shar-Pei.