Aloha! You're speaking to Dr. Michael Salkin
I'm sorry that your question wasn't answered in a timely manner. It's important to note that Malassezia (yeast) overgrowth is almost always associated with an underlying cause such as atopy
(allergies to environmental allergens such as pollens, molds, dust, and dust mites, etc.), food allergy, endocrinopathy, keratinization disorders (seborrhea
), metabolic disease, or prolonged therapy with corticosteroids. Shih Tzus are overrepresented as a breed.
His vet will need to identify the underlying cause and correct it for the yeast to be eliminated. For mild cases, topical therapy alone is often effective. The patient is bathed every 2-3 days with shampoo that contains 2% ketoconazole, 1% ketoconazole/2% chlorhexidine, 2% miconazole, 2-4% chlorhexidine, or 1% selenium sulfide. Shampoos that have two active ingredients provide better efficacy. Treatment should continue until the lesion resolve and follow-up skin cytology reveals no organisms - approximately 4 weeks.
The treatment of choice for moderate to severe cases is ketoconazole or fluconazole 4.5 mg/lb orally with food every 24 hours. Treatment should continue until the lesions resolve and follow-up skin cytology reveals no organisms (approximately 4 weeks).
Alternatively, treatment with terbinafine 2.3 mg-18.1 mg/lb orally every 24 hours or itraconazole (Sporanox) 2.3-4.6 mg/lb every 24 hours for 4 weeks may be effective. The prognosis is good if the underlying cause can be identified and corrected. Otherwise, regular once- or twice-weekly antiyeast shampoo baths may be needed to prevent relapse.
Please respond with further questions or concerns if you wish.