Sandra R. Merchant, DVM, Diplomate ACVD
Carol S. Foil, DVM, Diplomate ACVD
Malassezia (yeast) dermatitis is a common skin infection that is usually secondary to other skin disease. Malassezia is a yeast that can be found on normal canine skin, especially under the tail and in the ear. Under certain conditions, the yeast may proliferate and cause clinical disease.
Factors favorable to Malassezia proliferation include seborrhea, accumulation of moisture, and administration of antibiotics. Allergy and inflammation are thought to intensify the proliferation of the yeast.
Malassezia dermatitis can be localized or generalized. Animals can be mildly to intensely itchy. They often have a moist skin and a musty odor. The skin may appear thickened and may be reddened or greyish.
Malassezia dermatitis can be diagnosed by making impressions from the surface of affected skin, after clipping, and evaluating the surface cytology under the microscope. Finding more than 2-3 yeast organisms per microscopic field on 1000X magnification is abnormal.
The treatment of Malassezia dermatitis can be accomplished with topical and/or oral antifungal agents. Topical therapy is warranted in every case of Malassezia dermatitis. Topical products should initially be used two to three times weekly for generalized disease. Localized infection can be treated with topical antifungal creams or lotions. Oral therapy (ketoconazole - Nizoral7 or itraconazole - Sporanox7) is warranted in some cases of widespread Malassezia dermatitis. Improvement (but not cure) should be noted in 2 weeks. Treatment should be administered until the clinical signs have abated and no yeasts are seen on examination.
A search for an underlying disease or predisposing factors should be undertaken. If an underlying disease is not found or if predisposing factors are not addressed, the Malassezia dermatitis is likely to recur.
1) Bathe your dog with___________________, lathering for 5-10 minutes, followed by a complete rinse______________, times per week. You can spot-treat severely affected areas as often as daily
2) Apply__________________________________cream, spray or lotion to the affected areas____________times per day for____________weeks.
3) Give your dog_________capsules/tablets_____________times a day for__________weeks. If the medication seems to affect your pet=s appetite, please stop it and call us.
4) Follow-up examination and cytology is recommended in __________weeks. Please call for an appointment.