Last Lesson of the day: Canine Demodicosis

We humans, and our pets, carry around with us a large number of little organisms that are normal, and sometimes even healthy for us. For example, in our intestines we carry around a variety of "friendly" bacteria and when the balance of those good bacteria is thrown off, such as when we take broad spectrum antibiotics that kill them off, we can suffer ill effects such as intestinal upsets due to overgrowth of certain other bacteria or fungal species.

Just as it is normal for us to carry around certain bacteria in our intestines, it is normal for our dogs to carry around small numbers of a tiny mite called Demodex canis on their skin, down in the roots of the hair follicles. This mite is only transferred from mother dogs to their newborn puppies less than 3 days old whose immune systems have not developed. After that Demodex mites cannot be transmitted from one dog to another. Also, Demodex mites are species-specific, which means they only live on dogs.

Demodicosis, sometimes called Demodectic mange or red mange, is a condition that arises when the number of Demodex canis grows unchecked and causes skin irritation. There are two types of Demodicosis, localized demodicosis and general demodicosis. These two types are actually very different conditions with quite different implications.

Localized demodicosis affects dogs younger than two years old, most often puppies between 3 and 6 months of age (note: puppies do not have fully developed immune systems-- this is NORMAL). As the name suggests, localized demodicosis affects only part of a dog's skin, from 1 to 4 or 5 spots typically close together (though it can be on the face/head and the front legs and still be considered localized). The skin can become red and irritated in the area and the hair can fall out. Secondary infections can develop and can contribute to itchiness and discomfort. Localized demodicosis usually happens when a puppy is very stressed or when his or her immune system is affected by illness. It often resolves on its own without any treatment. Treatment can be used to speed up the process of killing off the excess mites, and might involve a topical ointment called Goodwinol, dips like Mitaban, or systemic medications like Ivermectin. There are also natural treatments that can be recommended by a homeopathic veterinarian.

Generalized demodicosis is a much more serious, severe disease. As the name indicates, it is generalized or affects the dog's whole body, and consists of baldness or patchy hair over the whole dog, scaly skin and accompanying skin infections. It has two sub-types, juvenile-onset (in dogs 8 months to 3 years depending on when the breed matures) and adult-onset (in mature dogs). Juvenile-onset generalized demodicosis has a much better prognosis than adult-onset, because a younger dog's immune system is continuing to develop and has a greater chance of being able to combat the mites on its own. Adult-onset demodicosis is usually indicative of an underlying immune problem and has a poorer prognosis. Generalized demodicosis requires treatment and testing to determine if there are the underlying conditions that affect the immune system in a mature dog. Treatment may involve antibiotics, Mitaban dips, Ivermectin, or other drugs.

Generalized demodicosis can be indicative of genetic disease that affects the immune system. Now let me emphasize something: localized demodicosis is NOT a genetic disease. These two conditions ARE NOT the same thing. A puppy who has localized demodicosis can grow up to be a perfectly normal, healthy dog and can be bred without any worry that the puppies will pass on this condition. An adult dog who has generalized demodicosis should be neutered or spayed and not bred, because it will almost always have some other underlying immune disorder.

In regard to Freja, Freja has localized demodicosis that occurred during her severe illness from Giardiasis. Freja had vomiting and diarrhea and became dehydrated. Also she was probably not receiving proper nutrients from her food due to malabsorption caused by an overabundance of Giardia. Adding insult to injury Freja developed Kennel Cough while she was hospitalized for IV fluids with the giardiasis.

Although we started to phase in treatment with Ivermectin she had a reaction to the Ivermectin (it caused her to have diarrhea), so we discontinued it after the second day before we even got up to the treatment dose. Freja's demodicosis is now resolving all on its own with NO specific treatment at all. Her hair is growing back on the bald spots and she has no new spots anywhere. This is a clear sign that Freja has completely recovered from the giardiasis AND the kennel cough and has a healthy immune system.