Abstract
The objective of this study was to characterize the histological appearance, prevalence, and association of pilosebaceous dysplasia (PD) in dogs with yeast dermatitis. A retrospective, light-microscopic study of H&E-stained skin-biopsy specimens from 670 dogs with non-neoplastic dermatoses and 28 normal dogs was performed. Chi-square and rank-sum analyses were used to compare the prevalence and abundance of PD in dogs with yeast dermatitis, normal dogs, and dogs with non-yeast dermatoses. PD was observed in 76 of 98 (78%; 95%confidence interval (CI) 68%, 85%) of dogs with yeast dermatitis and in 14 of 572 (2.4%; CI 1.4%, 4.2%) dogs with non-yeast dermatoses. PD was not observed in any normal dogs (CI 0%, 15%). The prevalence (presence, yes/no) of PD was significantly greater in dogs with yeast dermatitis (chi-square = 424.49; degrees of freedom = 2; p<0.0001) than in dogs with non-yeast dermatoses and in normal dogs. Also, among the dogs with PD present, the percentage of affected units in each dog was greater (p=0.0002) in dogs with yeast dermatitis (minimum 12%; median75%; maximum 100% affected units/dog) than in dogs with non-yeast dermatoses (minimum 3%; median 30%; maximum 100%). There was no significant difference (p≥0.05) between the prevalence of PD in dogs with non-yeast dermatoses and in normal dogs. These findings suggest that the finding of PD in skin-biopsy specimens of dogs is significantly associated with yeast dermatitis and could be considered when making this histological diagnosis.
