Cheyletiella

Cheyletiellosis is a mild dermatitis caused by mites of the genus Cheyletiella. It is also known as walking dandruff due to skin scales being carried by the mites. Cheyletiella live on the skin surface of dogs, cats, rabbits, and humans. The adult mites are about 0.385 millimeters long, have eight legs that have combs instead of claws, and have palpi that end in prominent hooks.^[1] 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.^[2] 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.

Additional recommended knowledge

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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.^[3] In unresponsive cases, ivermectin is used,^[2] Selamectin is also recommended for treatment.^[4] None of these products are approved for treatment of cheyletiellosis.^[5] Other pets in the same household should also be treated, and the house or kennel must be treated with an environmental flea spray.^[6]

Species

• Cheyletiella blakei Smiley, 1970 — infests cats (Felis catus), USA (Washington DC)
• Cheyletiella parasitivorax — infests rabbits (Oryctolagus cuniculus)^[2], France
• Cheyletiella romerolagi (Fain, 1972) — infests Romerolagus diazi, USA (New York)
• Cheyletiella strandtmanni Smiley, 1970 — infests hares (Lepus sp.), Taiwan
• Cheyletiella yasguri Smiley, 1965 — infests dogs

C. yasguri and C. blakei can transiently affect humans.^[1]

References

• Joel Hallan's Biology Catalog: Cheyletidae
• Griffin, Craig E.; Miller, William H.; Scott, Danny W. (2001). Small Animal Dermatology, 6th ed., W.B. Saunders Company. ISBN 0-7216-7618-9. 
• Mueller, Ralf S. (2005). Superficial mites in small animal dermatology (PDF). Proceedings of the 50° Congresso Nazionale Multisala SCIVAC. Retrieved on 2007-02-25.
• Scarampella F, Pollmeier M, Visser M, Boeckh A, Jeannin P (2005). "Efficacy of fipronil in the treatment of feline cheyletiellosis". Vet Parasitol 129 (3-4): 333-9. PMID 15845289.
• Ihrke, Peter J. (2006). New Approaches to Common Canine Ectoparasites (PDF). Proceedings of the 31st World Congress of the World Small Animal Veterinary Association. Retrieved on 2007-02-25.
• Mange in Dogs and Cats. The Merck Veterinary Manual (2006). Retrieved on 2007-02-25.
• Jeromin, Alice (August 2006). "Cheyletiella: The under-diagnosed mite". DVM: 8S-9S. Advanstar Communications.