We’ve all heard the term “scabby mutt.” But do you know what mange actually is and how it can affect your dog? Mange is a general term for two specific skin diseases in dogs caused by mites. These mites cause hair loss, sometimes severe itching and secondary skin infections. Only two types affect dogs – demodectic mange and sarcoptic mange.
Demodectic MangeSometimes called “red mange,” it is caused by the Demodex mite, a small, eight-legged, cigar-shaped parasite that lives in hair follicles. All dogs have some of these mites that live on their skin, as they are passed from mother to offspring (and are not contagious between dogs or contagious to humans). Usually these commensal mites do not cause any problems; however, illness can occur in young puppies with immature immune systems. It is greatly exacerbated if the puppy is malnourished and/or has other internal parasites such as roundworms or hookworms. Likewise, older dogs or dogs with compromised immune systems can develop mange.
Demodectic mange can be localized, causing foci of hair loss that don’t itch, or become generalized and severe, leading to complete hair loss, crusting, and secondary skin infections called pyoderma. This can be bacterial or fungal or both.
Sarcoptic Mange (called mange), on the other hand, spreads quickly between dogs and can infect humans as well. Sarcoptes is a short, stubby mite with eight legs. It causes intense itching as the mite burrows into the skin. This leads to significant discomfort, scratching, skin trauma, hair loss, and pyoderma (a bacterial skin infection).
get it checked
Have your dog evaluated by your vet if you notice any skin problems. Hair loss and crusting are common manifestations of many diseases, including flea infestations, food allergies, atopy and even liver disease or cancer. Therefore, if you have your dog checked by your vet, you can initially expect a basic diagnostic examination of the skin, including a skin scraping, cytological evaluation and discussion of your pet’s history and possible exposure to parasites and allergens.
The diagnosis of scabies mites is generally simple. If you have a new puppy with hair loss or a dog with intense itching and no apparent cause, your vet will perform a skin scraping as part of a dermatological exam. This involves taking a blunt scalpel blade and gently scraping the edges of a lesion. A little blood is expected, but this is not a painful or invasive procedure. The hair and skin on the blade are then transferred to a slide and examined under a microscope. Demodex mites are generally easy to find. Sarcoptes mites, because they tend to burrow deep, can be more of a challenge.
There is an “unofficial” test for sarcoptic mange called the pinnal pedal response. If you scratch behind a dog’s ear and he reacts as if it were intensely itching by banging his hind leg, this is considered consistent with a mange infection. Studies have even been conducted to evaluate the sensitivity and specificity of this maneuver and it was found to be very effective!
If your dog shows signs consistent with mange, and a skin scrape does not show mites, your vet will likely treat anyway, as the treatment is now safe and effective.
New and improved treatments
Until recently, treatment involved aggressive, repeated “dips” with foul-smelling chemicals such as lime sulfur. Dogs were bathed in this several times to kill the mites. The invention of modern parasiticides, especially those in the isoxazoline class, have largely made this treatment obsolete. These are oral and topical medications that prevent fleas and ticks and also treat mite infestations. They are safe, effective and readily available.
If your dog has generalized demodecosis leading to bacterial or fungal skin infections, you should also treat those with topical and possibly oral antibiotics and antifungals, and sedative baths, as well as fatty acid supplementation.
As always, when in doubt, check with your vet!
Signs and Symptoms
- itchy skin/scratching
- hair loss
- crusting/crusty skin
- pyoderma (bacterial skin infection)