We’ve all heard the term “mangy 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 of dogs caused by mites. These mites cause hair loss, sometimes intense itching and secondary skin infections. Only two types affect dogs — demodectic mange and sarcoptic mange.
✤ Demodectic mange, sometimes called “red mange,” is caused by the Demodex mite, a small, cigar-shaped parasite with eight legs that lives in the hair follicles. All dogs have a few of these mites living on their skin, as they are passed from mother to offspring (and are not contagious between dogs or infectious to humans). Most of the time, these commensal mites don’t cause any trouble; however, in young puppies with immature immune systems, illness can occur. It is significantly worsened if the puppy is malnourished and/or has other internal parasites such as roundworms or hookworms. Similarly, elderly dogs or dogs with compromised immune systems can develop mange.
Demodectic mange can be localized, causing focal spots of hair loss that are not itchy, or become generalized and severe, leading to complete hair loss, scabbing and secondary skin infections called pyoderma. This can be bacterial or fungal or both.
✤ Sarcoptic mange (called scabies), on the other hand, does spread rapidly between dogs and can also infect humans. 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 veterinarian if you notice any skin issues. Hair loss and scabbing are very common manifestations of many illnesses, including flea infestation, food allergies, atopy, and even liver disease or cancer. As a result, when having your dog checked by your veterinarian, expect a basic skin diagnostic workup initially including a skin scrape, cytology evaluation and discussion of your pet’s history and possible exposure to parasites and allergens.
Diagnosis of mange mites is generally straightforward. If you have a new puppy with hair loss or a dog with intense itching and no obvious cause, your veterinarian will perform a skin scraping as part of a dermatology workup. This involves taking a dulled scalpel blade and gently scraping along 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, as they tend to burrow deeply, can be more challenging.
There is an “unofficial” test for sarcoptic mange called the pinnal-pedal response. If you scratch behind a dog’s ear, and they respond as if this is intensely itchy by thumping their back leg, it is considered consistent with scabies infection. Studies have actually been conducted to evaluate the sensitivity and specificity of this maneuver and found it to be highly effective!
If your dog exhibits signs consistent with mange, and a skin scrape doesn’t show mites, your veterinarian will likely treat anyway, as treatment is now safe and effective.
Until recently, treating involved aggressive, repeated “dips” using foul-smelling chemicals like lime sulfur. Dogs were bathed in this several times to kill the mites. The invention of modern-day parasiticides, particularly those in the isoxazoline class, have made this treatment mostly 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, then you will also need to treat those with topical and possibly oral antibiotics and antifungals, and soothing baths, as well as fatty acid supplementation.
As always, when in doubt, check in with your veterinarian!
Signs & Symptoms
- itchy skin/scratching
- hair loss
- scabbing/crusty skin
- pyoderma (bacterial skin infection)