Does my pet have mange?
One of the most common questions asked by animal guardians whenever their pet has a skin problem is whether or not their pet could have mange. The term mange applies to a mite overgrowth on a pet’s skin. In canine medicine, the most common cause of mange is overgrowth of the demodex mite. Although low numbers of demodex mites are present on normal dog or cat skin, these mites will sometimes overgrow producing variable presentations of localized or generalized hair loss, crusting, and sometimes secondary skin infection.
By far the most common presentation of demodectic mange is in young pets under the age of one year, where a genetic immune deficiency is thought to be the underlying cause. Most common areas affected include the face, head, and forepaws often with focal area of hair loss; however, any area of the animal can be affected. Diagnosis is quite simple and based on skin scrapes done at a veterinary office, which are looked at under the microscope to identify the mites. This is NOT something that animal guardians can diagnose at home. In fact, in most pets over the age of one, skin allergies are the most common cause of hair loss, skin crusting, etc.
In many pets a localized form of demodectic mange often resolves on its own within weeks to a few months. But in other younger pets a more generalized form can develop affecting multiple areas on the pet’s body. Once a pet is sexually mature, demodectic mange is much less common until we hit middle age to older animals. During this phase, other immune-suppressive diseases or cancers, and even certain drug therapies like overuse of Prednisone, can on occasion cause overgrowth of demodex mange mites. It is important for animal guardians to know that this most common cause of mange is NOT contagious to other animals or people in the home.
The other type of mange seen in dogs is known as scabies mange. Scabies is usually acquired externally from either other dogs or rolling in dirt or grass, and causes INTENSE itching in most pets. The areas most commonly affected are the thinly haired areas on the pet such as the ear flaps, elbows, ankle areas of hind legs and the abdomen. Not only is hair loss present, but varying degrees of sores, crusting and secondary infections often accompany these very itchy dogs afflicted with scabies mites.
While skin scraping at the veterinarian’s office is again the common way of diagnosing this condition, 75% of the time skin scrapes can be negative because of the low number of mites on the pet’s skin. In those cases, veterinarians and veterinary dermatologists will often treat these itchy dogs if they suspect scabies mites (based on the clinical presentation), as these mites can potentially be passed to people and other dogs in the home.
Some veterinary dermatologists will suggest treating the home with products that kill fleas, as there is some suspicion that scabies mites may be able to live in the environment for a short period of time. I should say that both demodectic mange and scabies mange are a less common skin problem in cats. Treatment for demodectic mange may involve shampooing with a benzoal peroxide shampoo such as Oxydex Shampoo followed by Mitaban Dip every 1-2 weeks until the lesions resolve and skin scrapes are negative, or other products such as Ivomec in certain breeds, which is often given daily to severely affected pets. It can take sometimes several months for complete resolution to occur.
If scabies mites are suspected or confirmed by skin scrape, these can also be treated with Ivermectin once a week for one month, or using a prescription product like Revolution applied once every 2 weeks for 3 or 4 treatments. No matter which approach or medication is used, pets afflicted with either type of mange need to be under the care and supervision of a veterinarian, not only in which drugs are most appropriate, but also for follow-up skin scrapes to insure that the mange is completely resolved.