All You Wanted to Know About Mange, but Were Afraid to Ask

Welcome back!  I want to thank all of my loyal readers! Okay, there may be only ONE reader, Lexi, but maybe someone else read my column and didn’t have any comments.  Well that’s possible, isn’t it?  I’m going to keep writing, anyway, at least until Adrian makes me quit.

Lexi wanted me to discuss Mange in dogs, which fortuitously I know all about, and I don’t have to make anything up.  In fact, I’ve always been fascinated by parasitology, which always makes for good conversation at cocktail parties.  If you pay attention to the following, you too, will find yourself attracting a crowd at your next social gathering.

Interesting Cocktail Party Conversation Topic #1:  Beauty is Only Skin Deep

Let me first say that I hate the name, “mange.” I don’t know where that name came from, but I try not to call it that. There are two diseases in dogs that are called “mange.”  The only thing that they have in common is that they are both caused by microscopic skin mites.  But NOT THE SAME MITE.

First, I’m going to tell you all about Sarcoptic mange, also known as scabies in humans. This is a highly contagious disease caused by microscopic mites called Sarcoptes scabiei.   Here’s what one looks like:

Cute huh?

The male mites live on the surface of the skin. The females will burrow under the top layers of the skin forming tunnels and laying eggs along the tunnels. The female dies after laying her eggs. (Bummer) The eggs hatch into larvae and then molt into nymphs. When the nymphs reach the adult stage they return to the surface of the skin, mate, and the cycle starts over again. The entire life cycle of the mite is three weeks long.

The mites create small red bumps at the dogs’ elbows, ankles, chest, abdomen and the edges of the ears. The infected dog will scratch and bite at his skin causing more skin trauma which can result in a secondary bacterial infection. Advanced infestations will create crusty sores, patchy hair loss, and darkening of the skin. These dog mites will infect human skin, but I guess human skin doesn’t exactly get the cute little girl mite in the “mood” and they cannot reproduce on people.

Humans can develop a rash with very itchy red bumps, often under tight areas of clothing. This rash will go away on it’s own after a few days. The good news about Sarcoptic Mange is that it’s very easily treated and cured.

Now, let’s talk about the second type of mange. I prefer to call it Demodicosis. This can be a much more serious skin disease for dogs. Though a microscopic mite is also involved, a significant factor in the onset set of this skin disease is the dog’s defective immune system and genetic makeup. Demodex canis mites look like this:

The Demodex mite is often described in veterinary text books as “cigar shaped, “but I’ve never seen a cigar with eight stubby little legs, and I don’t think they would sell very well either.

These mites will live in small numbers on the skin of normal dogs, but for some reason when the dog’s immune system is weak, they reproduce in larger numbers and damage the skin. This can lead to extremely serious bacterial infections.

To confuse you even more, there are two forms of demodicosis.  1) localized and 2) generalized.  With the localized form, a puppy, usually less than one year old, will often develop areas of hair loss around its eyes or on its legs. Eighty five per cent of the time this disease will go away on its own, but about 15 per cent of dogs will develop the much more serious generalized form. The definition for attaining “generalized status” is having more than three areas of the body affected.

These dogs will often develop resistant bacterial infections, which they cannot fight off due their defective immune system. Demodicosis is NOT CONTAGIOUS to other dogs or to people.

Not that many years ago, generalized demodicosis could be a death sentence for my patients, as there were no effective treatments. This is no longer the case. We now have treatments that will control the mites and better antibiotics to control the infections. The course of treatment can, however, be a long one.

So, Lexi, I hope this helps. Maybe you can print this post and show it to the folks at the Dog Park?

Everyone else please feel free to leave your questions and I’ll pick one each month to answer in my column!

Dr. Grif Haber is a fifth generation Nashvillian. Dashing he parents’ hopes that he would become a “real doctor,” he earned his veterinary degree at Purdue University in 1972 and established Murphy Road Animal Hospital P.C. in 1977. With a heart for rescue, he founded Love at First Sight! Puppy and Kitten Adoption Center in 1995 that has since placed thousands of abandoned puppies and kittens into loving homes.