Demodectic vs. Sarcoptic Mange: All Manges Are Not the Same

Mange is a skin disease, primarily of dogs, although cats, ferrets and other animals can contract and spread mange.

There are 2 common forms of mange, and they are very different:

1. Demodex, caused by the Demodex mite
2. Sarcoptes, caused by the Sarcoptes scabiei mite (scabies)

When people refer to a stray dog as being a “mangy animal,” they are actually referring to the thickened skin and hair loss caused by the second one, the sarcoptic mange mite.

It’s one of those itchy conditions where you start talking about it and find yourself scratching just at the thought of it.

Demodectic vs. Sarcoptic Mange:

Demodectic mange:

• Not very itchy, unless it becomes generalized
• Most common in puppies and young dogs
• Begins with small hairless patches (alopecia)
• Localized and generalized forms
• NOT contagious to other animals or people

Sarcoptic mange:

• Itchy!
• Any dog can get it
• Ears, elbows and ventral areas affected most
• YES, contagious to other pets
• People can get infected, too, but it resolves quickly

I try to be careful in the exam room when pronouncing a diagnosis of mange because some people freak out. This panic attack probably comes from old ideas when mange was considered untreatable, or extremely difficult to treat.

The picture of a “mangy” dog comes to mind, in the middle of a junk yard, hunting for scraps, hairless, scabby and scratching. Fortunately, treatments for mange are very effective today.

Diagnosing Demodectic vs. Sarcoptic Mange

The skin lesions and history are enough to give your veterinarian a good idea of which mange mite we’re dealing with.

• Patchy, hairless lesions on a young pup: Think demodectic mange.
• An older dog who is scratching their ears and elbows off in the exam room: Think sarcoptic mange.

In vet school, we were taught a highly scientific and high-tech tool for diagnosing sarcoptic mange: If you scratch a dog’s ear, and the dog scratches furiously with a hind leg, you’ve got sarcoptic mange.

• Demodex mites are easy to find. Sarcoptes mites are not.
• Demodex lesions are pretty obvious. Sarcoptes symptoms can mimic allergic skin disease, food allergies and other conditions.

Unlike fleas, which are large enough to be seen with the naked eye, the Sarcoptes mite is microscopic. Not only that, but female mites like to burrow into the skin and lay eggs, which then hatch in pockets off of the burrow.

The eggs, larvae and feces are all likely to trigger an allergic reaction with extreme itching.

With severe sarcoptic mange, people in the house may have a skin rash that comes and goes. I usually ask my clients if they have been itching. If they say yes, that’s more evidence that sarcoptic mange may be the diagnosis.

When I mention mange as a possibility, my clients are often surprised because they looked through the pet’s coat and didn’t seen any mites — but as you now know, Sarcoptes mites are too small to see with the naked eye.

Sarcoptic Mange: Highly Infectious

Sarcoptes is a highly infectious parasite and readily passed between dogs or between wild animals such as foxes.

However, the mite is not picky, and in the absence of your dog will try munching on your skin. (Are you itching yet?)

Sarcoptes can’t live long on people. As a veterinarian, I’ve had it so many times that I’m not even grossed out by the idea anymore!

Only one thing about it bothers me: If I think I have a case of Sarcoptes, I go over all my skin cases of late to make sure I diagnosed a dog with scabies in the last week or so.

If I have Sarcoptes, I had to get it from somewhere! If I didn’t diagnose a dog with scabies recently, I go over my skin cases until I find it.

Symptoms of Sarcoptic Mange

Dogs with a Sarcoptes burden are itchy — very itchy — and if you touch their flanks it often triggers vigorous scratching with a back leg.

The dog may scratch so much that they damage the skin. Skin infections are a common consequence of mange. Typically the legs, the muzzle and edges of the ear are affected first.

The skin becomes thickened and inflamed, and some of the hairs fall out, giving an overall “moth-eaten” appearance.

However, mange mites respect no boundaries, and as the infection spreads, any part of the dog’s coat may be affected.

Eventually most of the fur falls out, and the skin becomes thickened, dry and infected. Incidentally, if you get your nose tuned into such things, mangy skin has a distinctive “mousy” odor about it.

Skin Scrape to Diagnose Mange in a Dog

How amazing is it that the vast majority of dogs don’t care when I take a blade to their skin and scrape away a little layer and place it on a microscope slide?

The blade is dulled, the scrape is quick, and it truly doesn’t hurt much.

Skin scrapes are the traditional way of diagnosing mange in a dog or other animal.

This involves moistening the skin with mineral oil and then blunt-scraping the skin’s surface until it starts to ooze blood. The sample of skin cells on the scalpel blade are transferred to a slide and examined under the microscope for the presence of mites.

However, there is now a blood test available that looks for the body’s immune response to the presence of the mite. The only downside is that the pet needs to be infected for at least a couple of weeks to mount a sufficient immune response that shows up on the blood test.

For a recent infection, skin scrapes are still the way to go.

Treatment for Demodectic Mange

Amitraz dips (Mitaban) or daily ivermectin are the most common drugs used to treat demodectic mange.

These drugs are not that old. Before their existence, a severe case of generalized Demodex could be a death sentence. Some cases are still difficult to treat, and some clients consider euthanasia.

Although some cases of generalized Demodex can take months to cure, with combinations of dips and oral medications, we usually achieve success.

But the labor-intensive dips, daily medications and repeat visits to the vet get many clients frustrated.

Dogs with 1–2 small Demodex lesions are considered to have localized disease. These may go away on their own without treatment.

Occasionally, a single lesion is found on an older dog, and we definitely don’t treat these cases unless the lesions spread.

Treatment for Sarcoptic Mange

Not too many diseases are revolutionized by the discovery of a drug, but that’s what ivermectin did for the treatment of Sarcoptes.

Do you all remember the commercial about “the heartbreak of psoriasis”? Well, the heartbreak of sarcoptic mange was a dog’s equivalent. Stinky lyme sulfur dips and baths were used with varying degrees of success before ivermectin.

Because certain dog breeds can be very sensitive to ivermectin, a newer, related product — selamectin (Revolution) — is a monthly topical heartworm preventive labeled to treat Sarcoptes and safe to use in all breeds. This, now, is my first choice for the treatment of sarcoptic mange.

Lyme sulfur dips can be effective. However, this dip smells like rotten eggs thrown on excrement. I hate to use it.

The Problem With Collies

I love collies and all the herding breeds.

Unfortunately, collies, Aussies and other breeds can carry the MDR1 gene (multidrug resistance gene) that makes the use of high doses of ivermectin out of the question.

We can treat these dogs with selamectin at normal doses.

Natural Remedies for Mange

Generalized cases of Demodex and Sarcoptes are serious. Left untreated or treated with ineffective products, the mite infestation becomes more difficult to treat.

The large majority of veterinary dermatologists don’t believe home remedies for mange are effective.

If you try recipes — including hydrogen peroxide, vinegar, borax and other household items — do yourself a favor: If you don’t see significant improvement quickly, get to the vet.

I checked with a number of holistic vet colleagues. They like to use natural immune system support products for mange cases, but the vast majority reach for dips or ivermectin to achieve a cure.

Treatment Failures

• When Demodex or Sarcoptes cases are not responding to treatment, the dog may have an underlying disease or be immunosuppressed.
• Older dogs who develop mange should undergo testing for endocrine, metabolic or neoplastic disease.
• If a dog is immunocompromised for any number of reasons, curing mange can be difficult. These dogs need a full medical workup.

Dog Breeds Most Likely to Get Demodectic Mange

Demodectic mange is more common in Bulldogs and Bulldog relatives, such as Boston Terriers, Pugs, pit bulls, etc.

Many other breeds are predisposed. Here is the list, probably not exhaustive:

• Collies
• Pointers
• Old English Sheepdog
• Beagle
• Dachshund
• Afghan Hound
• Dalmatian
• Shar-Pei
• German Shepherd Dog
• Chihuahua
• Great Dane
• Shih Tzu
• Fox Terrier

Hereditary?

Most vets recommend not breeding a dog with demodectic mange because of the genetic component.

Many breeders don’t like to hear this, and often insist “they have never seen it in their line before.”

I question their veracity in many circumstances. Puppies often clear a mild Demodex infection and unscrupulous breeders breed that dog or sell it as a potential breeder. Certainly, Demodex is prevalent in puppy mills.

If you think your dog is exhibiting any signs of demodectic or sarcoptic mange, get a diagnosis from your vet and begin treatment.

This pet health content was written by a veterinarian, Dr. Debora Lichtenberg, VMD, with contributions from Dr. Pippa Elliott, BVMS, MRCVS. This article was reviewed for accuracy by Dr. Elliott and was last updated Feb. 4, 2019.