Demodex: A Mitey Problem
We’ve all heard of mange. The term probably brings to mind a pitiful, skinny, bald little shelter animal in one of those heart-wrenching Sarah McLachlan ads on TV. Before you reach for the tissues, fear not! We can deal with mange! It’s not such a mighty problem! But it is a MITEY problem. There are several types of mange (like scabies, or sarcoptic mange), but demodectic mange is the most common type. The microscopic bugs, or demodex mites, that cause this condition are not contagious. They actually live on all dogs, but in low numbers. Here is a picture of the adorable little rascals!:
Cute, right? Not so much.
Luckily it is usually only in puppies or immunocompromised animals that the mites multiply and cause a problem. Some breeds, like pit bulls and shar peis, appear to be predisposed, so there is likely a genetic component to the immune system that leave some dogs more susceptible than others. Most cases of demodex mange are not a terrible, full body affair, though. Many dogs just get a few small patches of hair loss, often on the face, feet, and limbs. To test for these mites, your vet will perform a skin scraping. This is not a pleasant test, but most dogs tolerate it just fine. I always warn owners that the spots where I test are going to look like an angry hicky, and apologize in advance! If we see mites under the microscope, it’s a home run! Sometimes, though, we can’t catch the little guys in the act even if they are present. Hence the saying, we can rule mites in, but we can’t rule them out with a negative scrape test.
Treatment for mites varies by case. Very mild presentations may go away as a puppy ages. More significant cases require more aggressive care. Take Lily Bug:
Lily came to me as a 3 month old puppy that a very nice lady rescued from the lot next to her apartment complex, and boy did Lily look a little rough! We did a scrape, found a ton of mites, and started treatment. We needed to kill the mites, get rid of the secondary bacterial skin infection they had caused, and flush out the hair follicles where the mites lived. To kill the mites, we used to use a very high dose of a drug called ivermectin, but this medication can be dangerous to some dogs at the elevated doses needed to kill demodex. And, that drug had to be given EVERY DAY. Nowadays, I typically reach for a 3-month flea and tick pill called Bravecto (fluralaner). This medication is only labeled for dogs 6 months and older. It has been tested and found to be very safe in younger puppies, but puppy metabolisms are cranking so fast that they burn through the drug faster than adult dogs, so it might not last the whole 3 months. But, one pill typically cures a case of demodex, even one as bad as Lily’s! We also used antibiotics to get rid of Lily’s secondary bacteria, and a medicated, folicular flushing shampoo to clear all the debris out of her pores and follicles. In a couple months, Lily looked a heck of a lot better!
She’s even smiling to show off her spotted tongue! There are other treatments available, including medicated dips and off-label, high frequency administration of certain heartworm preventatives. But since its arrival on the market, Bravecto has been the easiest and most reliable treatment for me.
So don’t fear! If your dog has demodex mites, it’s not such a mighty problem. New treatments and some consistent care will get your puppy back to her cute and comfortable self.
Dr. Katie Morrill