When you hear “mange” you think “gross!” Well yeah, mites crawling all over your pet is a pretty gross thought, but I see a few cases a year, and we’ve all lived to tell. Often the owner is surprised when I tell them the diagnosis, and they think it relates to a lack of cleanliness. That is not at all true! Regardless of how “clean” your pet or house is, mites can be a possibility.
The two most common types of mite are Demodex and Sarcoptes.
Demodex is also called “puppy mange.” These mites are normally on ALL dogs in very very small amounts. However, some puppies do not have immune systems that are completely developed. They are unable to keep the mites in check, and can develop an overgrowth. Some puppies present with a small bald spot. Others may have more severe, generalized mange, to the point of being bald! These dogs also develop secondary bacterial infections and can become very sick. Demodex is easily diagnosed with a skin scrape test. The vet takes a scalpel blade, scrapes the skin down to a specific layer, then mixes the contents with oil and examines it under the microscope. The mites can be seen wriggling, waving, sometimes even mating!
Dogs with just a small bald spot can easily be treated with a cream that is applied. As the puppy grows, his or her immune system improves and the problem resolves. Generalized demodex is treated with systemic, oral medications, and sometimes also medicated baths. In rare cases, adult dogs can develop demodex. Because this is related to an insufficient immune system, the veterinarian will look for the underlying cause. Demodex itself generally is not itchy at all, unless it is severe and the skin is infected. It is not contagious to other dogs or to people.
Sarcoptic mange, also called scabies, is very different! It is VERY VERY itchy, and prednisone doesn’t stop the itch at all! It is also contagious to other animals and to people. These mites are difficult to detect on a skin scrape test. Therefore a negative skin scrape does not mean sarcoptes mites are not present. Often, the veterinarian will perform a skin scrape, but if it is negative, they will often treat, and the response to treatment indicates that the disease was in fact sarcoptes.
Stray dogs may have sarcoptes, but dogs who live in areas with wildlife (especially foxes) can be exposed as well. Therefore, if your dog is intensely itchy all of the sudden, contact your veterinarian!