Occurrence of Malassezia spp. in the external ear canals of dogs and cats with and without otitis externa.

We studied the lipophilic microbiota of the external ear canals of 332 animals (264 dogs and 68 cats), with and without otitis externa, over an 11-year period from 1988 to 1999. Malassezia pachydermatis was isolated from 62.2% and 50% of dogs with and without otitis externa, respectively, and from 41.2% and 17.6% of cats with and without otitis externa, respectively. In the group of animals studied for lipid-dependent species, these yeasts were isolated from 4.5% of dogs with otitis externa and from 23.1% and 8.9% of cats with and without otitis externa, respectively. M. sympodialis and M. furfur were isolated from cats and M. furfur and M. obtusa from dogs. Our findings show that lipid-dependent Malassezia species may contribute to the etiology of otitis externa in dogs and cats.