Demodicosis is a parasitic disease responsible for dermatological lesions. This disease is common in dogs, especially in young people, possibly due to genetic transmission. But sometimes some adult dogs can also be affected. Depending on the lesions, a more or less long treatment will be set up by your veterinarian. On the other hand, recurrences are possible and it is then necessary to be well informed about this disease.

Demodicosis is a disease caused by a parasite named Demodex canis. It is a mite naturally present on the skin of the dog, more precisely at the level of the hair follicles (place where the hair is born) and the sebaceous glands (glands which secrete sebum). This parasite is part of the commensal flora of many mammals including humans and has a cleaning role by feeding on dead skin and sebum. It is the mother who will transmit these parasites to the puppies during their first days. These parasites therefore live on the skin of dogs throughout their entire life cycle without causing them any problems in normal times. On the other hand, if they multiply abnormally, they can be responsible for dermatological lesions.

Young, immunocompromised dogs under 2 years of age are more likely to have demodicosis. Their immune system cannot control the number of Demodex present on the skin, resulting in significant proliferation. This lack of control is probably due to a genetic defect that has passed on to the puppies. It is therefore neither contagious from one dog to another nor contagious to humans.

This disease can also be present in adult dogs. In this case, it can be indicative of an underlying disease such as cancer or Cushing’s syndrome for example.

As these parasites are present in the hair follicles, their abnormal multiplication will cause hair loss, called alopecia. This alopecia can be localized to a specific place or be generalized in several places of the body. It is usually not itchy, meaning the dog does not scratch. These areas of alopecia are circumscribed and may be accompanied by redness and scales. In the event of localized demodicosis, the areas most frequently affected are the head as well as the legs (pododemodicosis). For generalized demodicosis, it is the limbs, neck and trunk that are most often affected. In addition, atrial demodicosis or otodemodecia (in the ears) which may be responsible for otitis is rare but does exist.

If you notice areas of red, scaly hair loss in your dog, you should see your veterinarian. Sometimes you may also notice the presence of comedones, small black dots. The veterinarian can then confirm demodicosis by a complementary examination called skin scraping. This involves scraping the skin using a scalpel blade. Several scrapings will be carried out in order to observe under the microscope the presence or not of Demodex and in what quantity. This examination is not painful for the animal.

In contrast, secondary bacterial infections are among the main complications. They can be responsible for pyoderma which can be serious. These painful secondary infections are often responsible for scratching in dogs. Skin ulcers can also appear. At an advanced stage, these complications can lead to impairment of the general condition of the animal with loss of appetite, loss of condition or even fever. It is important to keep in mind that in some cases the complications are so severe that the animal can die.

With regard to localized demodicosis, in a large part of the cases, the lesions regress on their own within a few weeks. But depending on the location, treatment may be necessary, especially in cases of otitis due to atrial demodicosis. If the lesions spread and do not resolve on their own, then you should see your veterinarian. In case of generalized demodicosis, a consultation is necessary before serious complications set in. It is important to keep in mind that the treatment for this parasitic disease is long and can extend over several months. In addition, the dog should be monitored regularly because relapses are still possible.

Your veterinarian can prescribe the best treatment for your animal based on the lesions it presents. Today there are 3 different forms of treatment:

• Solutions to be diluted;
• Pipettes spot-on ;
• Tablets.

In addition, antibiotics can also be prescribed in case of secondary bacterial infections.

For adult dogs with demodicosis, it is necessary to find the underlying cause and treat it.

This disease is not contagious, to avoid its appearance it is necessary to avoid as much as possible to breed animals affected by this disease to prevent its genetic transmission. All breeds of dogs can be affected. On the other hand, some remain predisposed like the Staffordshire Bull Terrier, the Dobermann, the Shar Pei or the Yorkshire Terrier to name but a few.