Image Quiz: Chronically pruritic and odoriferous ears in a basset hound (Sponsored by Intervet/Schering-Plough Animal Health), Answer E
Incorrect. While response to oral administration of itraconazole may be diagnostic for Malassezia dermatitis, it is not reliable for Malassezia otitis externa.1 Ototopical application is more likely to achieve effective drug concentrations in the ear, provided regular ear cleaning is adopted to remove exudate. Topical antifungal products licensed for Malassezia otitis externa are usually combined with a corticosteroid. Inclusion of a topical corticosteroid into the treatment protocol improves the efficacy of antifungal therapy by: 1. reducing the inflammation which is promoting yeast proliferation; 2. controlling hypersensitivity to the yeast, its by-products, or other complicating allergens; and 3. improving ear canal thickening/stenosis and restricting other chronic pathologic changes. Inclusion of an antibiotic prevents proliferation of bacteria that may occur if antifungal monotherapy is utilized.
1Pinchbeck LR, Hillier A, Kowalski JJ, et al. Comparison of pulse administration versus once daily administration of itraconazole for the treatment of Malassezia pachydermatis dermatitis and otitis in dogs. JAVMA 2002;220:12:1807-1812.
Acknowledgement: The author wishes to thank Ross Bond, DVM, BVMS, PhD, DVD, MRCVS, DECVD, for the use of the photo in this quiz and for his technical guidance.