Abstract

Malassezia spp. are commensal yeasts of canine skin that may act as opportunistic pathogens. The aim of this study was to assess the presence, distribution and numbers of Malassezia spp. on the skin and external ear canal in clinically healthy Golden Retrievers and Bernese Mountain Dogs, to evaluate the influence of breed, age and sex, and to compare the findings with previously published cytological reference values. Fifty clinically healthy Golden Retrievers and 50 Bernese Mountain Dogs were included in the study. Both external ear canals and six body sites (perioral region, chin, axilla, interdigital spaces, inguinal region and dorsum) were sampled. The external ear canals were sampled using a sterile cotton swab, while the skin sites were sampled using the adhesive tape technique. The slides obtained were microscopically examined, and the number of Malassezia spp. was recorded. All data were statistically analyzed. Malassezia spp. were observed in all dogs, with different distributions in ear and skin areas. Malassezia spp. counts were significantly higher in Golden Retrievers than in Bernese Mountain Dogs at all skin sites. No significant difference was observed between breeds in the external ear canal. Forty-nine (98%) Golden Retrievers and 35 (74%) Bernese Mountain Dogs showed a mean skin number of Malassezia spp. per oil immersion field (OIF) above the 1 yeast/OIF literature threshold commonly used in the presence of clinical signs. No relationship was found between the mean value of Malassezia spp. per microscopic field and sex or age in either breed. The results show that Golden Retrievers have higher Malassezia spp. counts across all evaluated skin sites compared with Bernese Mountain Dogs. Whether higher baseline Malassezia spp. populations contribute to clinical yeast overgrowth requires further investigation. No significant difference in external ear canal Malassezia spp. counts was observed between breeds; however, the mean values recorded in both populations exceeded cytological reference values for healthy dogs. These findings indicate that cytological Malassezia spp. counts in clinically healthy dogs may vary according to breed and anatomical site. Diagnostic interpretation should therefore integrate cytological findings with clinical signs, breed, site, and sampling method. Further studies are required to establish normal reference intervals for Malassezia spp. per microscopic field based on breed and anatomical site.

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