Demodex Mite

Over the years of working as a veterinarian, my list of “special” patients, keeps expanding. One of the most memorable cases I will always have in my repertoire is Zeiss. Zeiss is a dog of the Catahoula breed. Zeiss was about 3 months old when he first came to see me at my practice. You could smell Zeiss' presence in the premises before you even saw him. Zeiss and his owners were miserable. He was just starting his life. Instead of having a joyful experience of adopting a new and adorable puppy, his owners had experience so much grief of seeing him suffer, lose his fur, his skin was red and extremely irritated and his entire being was just miserable. They came to see me as they were very desperate, but soon we found out the root of Zeiss' problem.  It was a mange of Demodex mite.  Two months into the treatment, Zeiss is doing SO much better, and both he and his owners are loving life again.

Demodex is a type of mite that occurs naturally in dogs' hair follicles, in low numbers. In a normal healthy dog, Demodex stays subclinical and does not cause any problems to the dog. In some cases there may be suppression of the immune system due to various possible causes. Some of the conditions that suppress the immune system are: fighting a concurrent disease, old age, very young age, nutritional deficiency, stress, and more.

When the immune system is suppressed, the mite population overgrow leading to a reaction that can range between mild irritation and hair loss on a small patch of skin to severe and widespread inflammation, and secondary infection affecting most or the entire dog’s body. Demodex infection is called Demodicosis or Demodectic mange.

The clinical symptoms of Demodicosis are hair loss, the skin becomes dry and scaly, there is redness of the skin, pustules (pimples), and the skin is warm to the touch. The condition sometimes involves irritation and itchiness, and sometimes not. Typically the dog emits a strong, very unpleasant odor.

Early infestation usually involves lesions on the face, around the eyes, or at the corners of the mouth, and on the forelimbs and paws. An advanced infestation can spread and cover most of the dog’s body.

The diagnosis consists on finding the Demodex mite in a skin scraping sample taken from the affected dog, under a microscopic examination. In order to take a sample that would yield a conclusive result, the skin scraping has to be done deep enough to reach the hair follicles. Typically, a sample is considered legitimate if the area has been scraped until blood appears. Because the mite is a normal inhabitant of dog’s hair follicles, there is a discussion whether finding the mite on a slide is a conclusive diagnosis.

In advanced cases, an underlying condition that promoted the demodectic mange development, should be looked for. Occasionally, other tests may be required in order to pin down the underlying condition.

Early, mild localized cases, may heal on their own. Localized demodectic mange is considered a common puppyhood ailment, with roughly 90% of cases resolving on their own with no treatment.

Generalized cases can be very challenging to resolve. There are few products and protocols available for treating demodectic mange. In my own experience, I have found that dipping the dog in a special solution, once or biweekly for few weeks is the best protocol for eradicating the infestation. Antibiotics are often required for the treatment of secondary bacterial infection of the skin.

The condition is considered infectious, however, dogs can only transmit the mite in a very close contact - for example puppies and a nursing mom. The transmission of these mites from mother to pup is normal (which is why the mites are normal inhabitants of the dog's skin) but when the puppy's immune system is not strong enough it can lead to the development of clinical demodectic mange.

In normal contact between dogs, the disease should not pass.

Although humans and cats can also suffer from demodectic mange, the mites are specific to their hosts, hence the disease cannot be transmitted to other animal species, nor to people.  

If any of what is mentioned here raises a red flag regarding your dog, take it to see your vet. Generalized demodicosis is a severe, life debilitating condition. Nobody wants to see their once furry friend in that condition. Plus, honestly, nobody wants to share their life with a smelly dog. Do not procrastinate, seek veterinary help. Remember that there are few different options and protocols to successfully treat demodicosis. If one route does not lead to healing, seek more information from your vet on other treatment options.