Dogs with Demodectic Mange
Demodicosis is caused by a small, cigar-shaped mite called (Demodex Canis or Injai). Like Sarcoptic Mange, these mites can only be seen under a microscope, they are too small to be seen with the naked eye. Demodex Mites live in the hair follicles, oil glands, and skin of dogs. Demodex mites are commonly found on healthy dogs with no clinical signs in low numbers. They are usually just a part of the normal flora on a dog’s skin and in their fur. For reasons that are not completely understood, young dogs or dogs with an underlying immune system disorder can develop clinical signs from these mites. Demodex mites are species specific, meaning that they are not contagious to other species.
Most commonly, puppies are the dogs we see which have clinical signs of Demodectic Mange. Circular areas of hair loss, about a quarter in size sometimes seen with additional crusting in a young dog, are the hallmark of recognizing this disorder. In this author’s opinion, dogs with Demodectic Mange are mildly itchy or not itchy at all. Most owners tell me their dog is about a 3 out of 10 itchy. This compares with patients who have Sarcoptic Mange, where owners report their dog is a 10 out of 10 on the itchiness scale!
The specific form of Demodicosis is usually divided into categories, in an effort to determine when treatment is warranted. Cases are broken down into juvenile vs. adult onset based on the age of the dog when symptoms appeared. Cases can then be further broken down into a localized vs. generalized form. In most cases, juvenile dogs with only one area affected who are not itchy are best not to treat. Fortunately, the hair loss will resolve naturally as the puppy grows up and their immune system develops. In more severe cases where multiple areas of the body are affected, your veterinarian may elect to begin treatment.
Diagnosis of Demodex requires your veterinarian performing a skin scrape. This routine test involves scraping your pet’s skin with a surgical blade in order to acquire a sample. This sample is then looked at under a microscope in an attempt to identify the small, cigar-shaped mites.
When a diagnosis of Demodicosis is confirmed by a skin scraping, treatment can be instituted. Fortunately, there are many treatment options available, ranging from oral, liquid anti-parasitic treatments given once daily, to weekly dips with a medicated shampoo. There are also certain prescription oral flea/tick preventatives which have been shown to help clear the mites from the skin of dogs. These treatments are generally very successful, although re-check visits once monthly must demonstrate at least 2 to 3 negative results before treatment should be concluded.
If you think your dog has Demodectic Mange, we recommend scheduling a visit with a member of our Veterinary Team. Please be sure to mention if other dogs in your house are affected, as well as the type and frequency of Flea/Tick prevention your give your pets.
Jeffrey Stupine, V.M.D
Medical Director, World of Animals Veterinary Hospitals