The Mexican Hairless Dog as a Model for Assessing the Comedolytic and Morphogenic Activity of Retinoids

The study used the Mexican hairless dog, which naturally has comedones, to evaluate the comedolytic activity of three different formulations of tretinoin over 14 weeks. All formulations significantly reduced the number of comedones and improved skin color uniformity. Histological changes were consistent with those seen in humans treated with tretinoin, and a novel observation was the incomplete neogenesis of hair follicles. The researchers concluded that the Mexican hairless dog could serve as a valuable model for screening new retinoid compounds.