Malassezia pachydermatis presence in canine external otitis and dermatopathies

Malassezia pachydermatis is a commensal yeast of the skin and external ear canal of dogs and cats that may become an opportunistic pathogen under some conditions. The aim of this paper was to research the diseases which predispose to the development of opportunistic M. pachydermatis in dogs with external otitis or dermatopathies. The samples were collected by sterile swabs or by the carpet technique. Samples were obtained from the external ear canal and cutaneous tegument and were seeded in Sabouraud dextrose agar added with chloramphenicol and cycloheximide. Following, they were incubated at 32oC for seven days for yeast identification. M. pachydermatis isolation was successful in 49 (70%) of the 70 samples investigated. Underlying diseases diagnosed in these animals included ceruminous otitis, skin fold pyoderma, seborrhoeic dermatitis, atopic dermatitis, pressure point pyoderma, parasitic otitis, acanthosis nigricans, hot spot and bacterial otitis. The results confirm that the presence of this yeast can cause the perpetuation of these diseases and be a treatment complication factor. Key words: Malasseziosis, dogs, otitis external, dermatopathies.