Demodex are parasitic mites that cause a skin condition called demodicosis. These microscopic monsters can live in your dog’s hair follicles and oil glands.
While all dogs have a small population of these little pests (disgusting, I know), those who are sick or have a compromised immune system can’t suppress the mites from spreading, and so an infestation can occur. This sometimes occurs in dogs without an obvious underlying problem.
Demodicosis can be localized or generalized. Localized demodicosis infections usually occur early in life, typically in puppies between 3 and 6 months of age. This form of of the disease is usually mild and responds well to treatment. Many cases resolve spontaneously with little or no treatment, though in some dogs it progresses to the generalized form. Generalized demodicosis can also occur in older dogs and is then often secondary to an underlying disease that is suppressing the dog's immune system. Generalized demodicosis is more difficult to treat and carries a more guarded prognosis.
With localized demodicosis, symptoms are usually mild and affect a dog’s face, trunk, or legs. You will notice thinning hair, scaly skin, and the skin itself will appear reddish-brown and look very itchy. With generalized demodicosis, skin lesions are more widespread and may involve the entire body. Your dog may look scruffy and show signs of hair loss as well as discoloration of the skin. She may also be lethargic and have a poor appetite.
In order to diagnose your dog with demodicosis, your veterinarian will take skin scrapings of the affected areas and may recommend other tests specific to your dog’s symptoms and the severity of the infestation.
The treatment for demodicosis will vary depending on whether the infection is localized or generalized. Localized demodicosis often requires no treatment other than careful observation. As stated above, the good news is that, most often, localized infestations resolve themselves without treatment! Generalized demodicosis is treated with oral or topical medication depending on the individual case. In some situations, additional medications are prescribed, such as antibiotics if a secondary bacterial infection has occurred. Regularly scheduled recheck examinations and skin scrapings are needed to monitor response to therapy.
For more information about the treatment of demodicosis, visit http://www.capcvet.org/recommendations/demodex.html.
Maintaining your pooch’s health is the best way to prevent her from contracting demodicosis. A healthy environment, good diet, and regular veterinary checkups will help your dog be in the best possible health! The good news about demodicosis is that it is NOT contagious to other dogs, cats, or humans!
If you have any questions or concerns, you should always visit or call your veterinarian – they are your best resource to ensure the health and well-being of your pets.
Peter Kintzer DVM, DACVIM
Canine Demodicosis - Skin irritating mites in dogs - pets
Mites are to dogs what the common cold is to humans: contagious and prevalent enough that most dogs have experienced it.
Not all cases of mites are problematic. In fact, most infestations occurring among puppies resolve themselves. These microscopic, transparent, crab-like parasites are just a part of life. But there are certain types of mite infestations that can cause skin irritation and result in more serious health complications if left untreated. Even dogs who are well-cared for can develop mite infestations that will become harmful if left unmanaged.
Types of Dog Mite Infestations
Mite infestations that cause skin irritation are also called “mange.” But getting down to the nitty gritty, there are four types of mites that result in noticeable symptoms and effects. They include:
- Sarcoptes scabiei - Also known as canine scabies, these burrow into the skin rather than merely reside on its surface
- Otodectes cynotis - Ear mites marked by a black or brownish-red crust in the ear
- Demodex canis - Live in hair follicles and are common even on healthy dogs, but can cause demodectic mange
- Cheyletiella yasguri - Mites that reside on the surface, also known “walking dandruff”
While it’s not particularly pleasant to think of tiny parasites riding around on your furry best pal, demodex mites in particular are often found on healthy, well-cared for dogs. Their presence isn’t problematic unless the dog’s immune system is compromised and cannot fend off overpopulation. When the mite population increases, it results in itching and inflammation, which can ultimately lead to a bacterial infection. Pets with weak immune systems will be more likely to develop bad cases of mites.
While minor cases of demodectic mange are common among puppies and usually clear up on their own, certain risk factors may make the infestation harder to get rid of and more problematic. Stress, an unclean environment, cases of intestinal heartworms, and infections can all increase the risk of developing a problematic case of mites. Pregnant and nursing dogs and their puppies are also at higher risk.
Untreated demodectic mange can be deadly. If you see patchy skin on the face, your dog may be suffering from this type of mange, which will eventually spread all the way to the rear. Demodectic mange in puppies is usually localized, while older dogs more often suffer from generalized demodectic mange. Visit a trusted veterinarian immediately if you suspect your dog may have this type. If your dog is experiencing these systems, it’s important to treat with a safe spray or shampoo bar that will eliminate the mites on the skin and provide soothing relief.
You may recognize “demodex mites” as a parasite that can also live on humans but before you get chills up your spine, you should know that your dog cannot spread its particular brand of demodex mites to you even though the condition is contagious as it relates to pets.
When in close contact with the Cheyletiella or Sarcoptes mite, you as the owner may develop a patch of discoloration or minor red rash. This isn’t serious and should clear up with a shower or bath.
Diagnosing and Treating Demodicosis
Diagnosis is based on signs of the disease and finding the parasite in skin scrapings or biopsies. Occasionally treatment is not necessary for localized demodicosis, which may clear up by itself.
Generalized demodicosis requires aggressive therapy, however. Typically, the pup is shaved to offer better access to the skin and is given weekly or every-other-week whole-body dips with a miticidal preparation prescribed by the veterinarian. Some puppies and breeds are sensitive to these preparations, though, and may suffer side effects such as drowsiness, vomiting, lethargy, and drunken behavior. Use such products only with veterinary supervision.
Antibiotic therapy is required to fight secondary infections. Repeated baths with exfoliating shampoos such as those containing benzoyl peroxide are helpful.
Unfortunately, dogs suffering from generalized demodicosis have a guarded prognosis and may never achieve a cure. Euthanasia is sometimes the kindest choice. Because of the potential heritable components involved in this disease, dogs that have suffered generalized demodicosis should not be bred.
How to spot miteson dogs
The three mite species most commonly infesting dogs are Demodex mites, Sarcoptes mites and ear mites.
Demodex mites are actually a normal inhabitant of your dog’s skin. These mites live in the hair follicles of dogs and are passed from the mother to her pups during nursing. The dog’s immune system normally controls the number of mites, so that they cause no harm. Dogs can develop signs of disease if their immune system is unable to control the mite population. This most commonly occurs in young or malnourished dogs, or those with other diseases that compromise their immune system. Signs of disease due to Demodex mites include hair loss, thickening of the skin, and skin infections.
Sarcoptes mites not only affect dogs, but can also be transmitted to humans. The mites easily pass from an infested dog to other dogs that are in close contact. The Sarcoptes mites burrow into the skin, leading to intense itching, hair loss, and skin infections. Confirming a diagnosis of Sarcoptes mites can be difficult as the mites live within the skin. Your vet may need to examine a skin scraping under the microscope to identify the mites.
As their name suggests, ear mites inhabit the ear canals and surrounding skin. Signs of infestation typically include skin irritation scratching around the ears, head and neck head shaking the presence of an ear discharge that is dark and waxy (resembling coffee grounds) and an unpleasant odour from the ears. Ear mite infestation may also allow for a secondary bacterial or yeast infection to occur in your dog’s ears. Your vet can diagnose ear mites by looking at a sample from the ear canal, under the microscope.
Protecting your dog from mites
Protect your dog from mites with NexGard ® or NexGard SPECTRA ® . Just one monthly chew treats and controls the three most common mites infesting dogs in Australia: Demodex mites, the cause of demodectic mange Sarcoptes mites, the cause of sarcoptic mange (also known as scabies) and ear mites.
Both mites can be treated using a antiparasitic medication called ivermectin. Generally Sarcoptes mange is easier to control and takes around four weeks to resolve. Demodex mites on the other hand can spontaneously resolve in puppies as their immune system develops. But in older dogs or severe cases treatment has to continue until at least two negative skin scrapes are performed two weeks apart. This can take many months to resolve, and if the symptoms return it almost certainly means treatment was not continued long enough.
Ivermectin can have side effects including seizures, and should never be used in Colliebreeds as they lack the enzyme to convert the drug. other antiparasitic medication can be used to treat both kinds of mange but many are even more toxic than ivermectin, or have very mixed results. ivermectin can be given orally or as an injection once a week for the duration of treatment.
Have you tried other treatments successfully in your dog? If so leave a comment to tell us what you used!
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