Also Known As: Walking Dandruff, Cheyletiellosis

Transmission or Cause: Cheyletiellosis is caused by infestation of large mites who live on the surface of the skin. The mites spend their entire life cycle on the host. They are highly contagious, especially among young animals. Adult female mites are able to live off the host for up to 10 days.

Affected Animals: Cheyletiellosis affects dogs and cats as well as rabbits and humans. There may be a higher incidence in Cocker spaniels.

Clinical signs: The dogs and cats affected with Cheyletiella mites can either be intensely itchy or hardly itchy at all. They will frequently get a dry scale along their backs which can spread to more severe and body-wide scaling. As the infection progresses, the itching becomes more severe. Patchy hair loss can occur due to severe scratching. Some cats may have very few signs other than self-induced hair loss from chewing/pulling out their fur. In humans, Cheyletiella mites cause a red raised rash on the arms, trunk and buttocks that eventually turns into a yellow-crusted area. Human infections usually resolve in 3 weeks if the host animal is treated.

Diagnosis: The definitive diagnosis of cheyletiellosis is made by identifying the mites or their eggs. Scale can be collected by clear tape impressions, flea combing, or superficial skin scrapings which is then examined under the microscope. Cheyletiella mites may be impossible to find in cats. If cheyletiellosis is suspected in your pet, treatment may be recommended even if no mites can be found.
Prognosis: The prognosis for cheyletiellosis is good.

Treatment: Treatment of cheyletiellosis involves weekly treatments with pesticides like lime sulfur dips or prescription spot-application pesticides. Household or environmental treatment is usually not necessary.

Prevention: Cheyletiellosis is usually not a problem in pets that are routinely treated with flea control products.