By Dr. Becker
Demodectic mange or demodicosis is an inflammatory skin condition that is caused by Demodex mites that can’t be seen with the naked eye. These mites are commonly found on the skin of mammals and usually don’t cause a problem. But when an animal’s immune system is weakened by illness, stress, or genetic predisposition, the mite population can grow out of control, causing skin and coat issues.
Demodectic mange is quite common in dogs, but not in cats. Because the condition is relatively rare in kitties it hasn’t been closely studied, which means much of what we know about the problem in dogs is extrapolated to cats. This includes the fact that some sort of immune suppression seems to be necessary in order for the Demodex mites to actually cause an infection.
There are two types of Demodex mites in cats: Demodex cati and Demodex gatoi. Demodex cati is a long, skinny mite that lives inside the hair follicle. Demodex gatoi is a short, stubby mite that lives in the skin. Demodex cati is thought to be a normal inhabitant of feline skin, while Demodex gatoi is probably an opportunistic infectious parasite. Demodex gatoi may be transmissible among cats, and is slightly more prevalent than Demodex cati infections.
Symptoms and Diagnosis
Symptoms of feline demodicosis include extreme itchiness (especially when Demodex gatoi is present) and hair loss around the eyes, head, neck, and flank. Lesions on the skin may also develop, as well as scales and crusty patches.
To accurately diagnosis demodectic mange, skin scrapings are necessary to detect and identify the mites. Hair samples may also help identify the specific type of mite involved. A urinalysis and bloodwork, including viral and immunoglobulin testing, may also be done to look for other potential metabolic or immune-related issues that could be causing the cat’s skin condition.
Two things can hamper diagnosis. Number one, Demodex gatoi mites reside superficially in the skin and can actually be licked away by the cat during grooming. Number two, the condition is so rare in cats that many veterinarians don’t think to look for it.
Demodex gatoi mites can also be seen in fecal flotation tests. Sometimes, this method actually provides a faster and more definitive diagnosis. If mites are detected in a stool sample, it is a confirming diagnosis. The mites can be missed on a skin scraping, or sometimes there aren’t enough of them present on the fur or skin because the cat has licked them off. So it’s actually possible to have a kitty who is positive for Demodectic mange, but whose skin scrapings are negative.
Treatment of Demodectic Mange in Cats
The good news is that treating demodicosis in kitties is not difficult.
My favorite treatment and the safest approach is a lime sulfur dip done every 5 to 7 days for a minimum of 6 weeks or longer, until the skin scrapings are negative. You can get lime sulfur dip from your vet, or online. A higher concentration -- 8 ounces of sulfur mix in 120 ounces of water -- can be used to speed up the process. The solution should thoroughly soak into your kitty’s coat and skin (avoiding her eyes, of course), and should not be rinsed off. Your cat must be kept warm and in a well-ventilated area after she’s dipped.
Unfortunately, lime sulfur dips are incredibly stinky -- but they’re really effective. Also, the solution will discolor jewelry, towels, and light-colored fur, so you’ll need to take necessary precautions. Keep in mind that your cat will hate the dips, and kitties with light coats may be temporarily discolored, but alternative treatments, including Ivermectin and similar agents, have serious adverse side effects. I don’t recommend them.
Since Demodex gatoi is contagious, if there are other cats living in close contact with an infected kitty, they should also be tested for the presence of mites and receive treatment if necessary.
Keep your cat’s immune system in balance by reducing stress, feeding a species-appropriate diet, and avoiding unnecessary vaccines. All of those things will help reduce or prevent conditions like demodectic mange, which occurs primarily in animals with immunosuppression. If you haven’t had your demodex positive cat tested for infectious viruses such as feline leukemia and FIV, I recommend doing so. Also consider having her immunoglobulin levels (IgG, IgA, and IgM) measured. There are many immune building herbs and supplements your holistic vet can prescribe depending on the reason your cat is immunosuppressed.