The Malassezia pachydermatis ( Pityrosporum canis) is found in the whole skin microflora. It seems to occur as a consequence of changes in the local microenvironment, such as moist increase, temperature or substrate enhancement, generating a raising on cell quantity, which brings the transition from commensal form to parasitism. The purpose of this work was to evaluate the prevalence of M. pachydermatis infection and other infectious agents in external otitis and dog dermatitis as well. We also examined 78 samples of dogs suffering from otitis, 36 samples of dogs having normal auditive tube and 24 having dermatitis. All samples were submitted to direct microscopic examination. They were cultured in blood agar, also in Sabouraud agar dextrose with cloranfenicol and cicloheximide. By direct examination showed that 50% of the samples on dogs with otitis and dermatitis 16.6% showed several cels resembling M. pachydermatis. However from healthy ear sample 83.3% did not present cells with this form. M. pachydermatis was isolated on 80.7% of otitis samples, on 25% of normal auditive tube samples and finally, 37.5% of dog dermatitis samples. It was isolated Staphylococcus intermedius, S. aureus, S. epidermidis, Pseudomonas aeruginosa, Proteus sp, Streptococcus sp and Otodectes cynotis from samples of animals with otitis. Cases of dermatites allowed also the isolation of Staphylococcus intermedius, S. aureus, S. epidermidis, Microsporum canis, M. gypseum, Trychophyton mentagophytes and Demodex canis. M. pachydermatis was the most prevalent agent in cases of external otitis and dermatitis, being an opportunistic agent, that cause otitis and dermatitis when thereis a change in the microenvironment
Malassezia pachydermatis; otitis; dermatitis; dog
