Malassezia pachydermatis is the yeast organism most commonly involved in otitis externa. This is not surprising, since Malassezia is normally found within the ear canals of healthy cats, causing no problems whatsoever.
However, if inflammation strikes for whatever reason, the yeast takes advantage of a good situation and begins to proliferate. When this growth reaches a certain level, it too can promote inflammation. A characteristic brownish discharge is seen with a buildup of yeast within the ears.
Ear ointments or solutions containing miconazole, thiabendazole, or nystatin can be used to effectively treat yeast infections in the ear. Treating the ears twice daily for 10 to 14 days will clear up most infections.
Because Malassezia is considered an opportunist, it is important that the underlying source of the inflammation that led to the yeast infection be identified and treated concurrently.