Which organism is frequently recovered from the ears of dogs with chronic otitis externa?

• A. Malassezia sp.
• B. Candida sp.
• C. Cryptococcus sp.
• D. Microsporum sp.

Answer: (A)

Chronic otitis externa in dogs is often driven by overgrowth of a yeast that normally lives in the ear canal. Malassezia pachydermatis is a lipophilic yeast commonly found on canine skin and ears, and it thrives in the warm, moist environment created by inflammation. When this overgrowth occurs, it contributes to discharge, odor, and itching, so it is frequently recovered from affected ears. Among the other organisms listed, Candida can be seen but is less commonly the primary culprit in chronic ear infections; Cryptococcus typically involves systemic or distant sites rather than the ear; Microsporum is a dermatophyte more associated with skin infections like ringworm rather than chronic otitis externa. Thus, Malassezia is the most consistent and frequent finding in these cases.