Cheyletiellosis

Cheyletiellosis is a mild dermatitis caused by the Cheyletiella species of mites. It is also known as walking dandruff due to skin scales being carried by the mites. Cheyletiella are large mites that live on the skin surface of dogs, cats, rabbits, and humans. The adult mites are about 385 micrometres long, have eight legs that have combs instead of claws, and have palpi that end in prominent hooks. They do not burrow into the skin but live in the keratin level. Their entire 21 day life cycle is on one host. They cannot survive off the host for more than 10 days. Cheyletiellosis is seen more commonly in areas where fleas are less prevalent, because of the decreased use of flea products that are also efficacious for the treatment of this mite.

Cheyletiellosis is highly contagious. Transmission is by direct contact with an affected animal. Symptoms in animals vary from no signs to intense itching, scales on the skin, and hair loss. The lesions are usually on the dorsum of the animal. Symptoms in humans include multiple red, itchy bumps on the arms, trunk, and buttocks. Because humans are an irregular host for the mite, the symptoms usually go away in about three weeks.

Diagnosis is by finding the mites or eggs microscopically in a skin scraping, combing, or on acetate tape applied to the skin. The most common treatment in animals is weekly use of some form of topical pesticide appropriate for the affected animal, often an anti-flea product. Fipronil works well, especially in cats. In unresponsive cases, ivermectin is used, Selamectin is also recommended for treatment. None of these products are approved for treatment of cheyletiellosis. Other pets in the same household should also be treated, and the house or kennel must be treated with an environmental flea spray.

Cheyletiella species
C. yasguri and C. blakei can transiently affect humans.
 * Cheyletiella yasguri - infests dogs
 * Cheyletiella blakei - infests cats
 * Cheyletiella parasitivorax - infests rabbits