Alopecia Areata in a Dog: Clinical, Dermoscopic and Histological Features.

Alopecia areata (AA)-like disease is characterized by multifocal patchy hair loss in humans, rodents, dogs, and horses. Remarkable similarities between human and nonhuman AA cases have been reported in terms of clinical presentation, histology, and immune mechanisms of the disease. Canine AA-like lesions most often consist of well-demarcated alopecic patches, frequently but not only involving the face and the head, which extend to the ear pinnae and legs. In some cases, hair loss can have a more generalized distribution. As in humans, hair regrowth is most commonly spontaneous in canine AA-like disease and the resistant cases usually respond to glucocorticoids or cyclosporine treatment. Diagnosis of AA in veterinary medicine relies on presentation, histopathology, and immunohistochemistry and on regrowth following therapy. This case report describes the first dermoscopic evaluation of AA-like disease in a dog with a clinical presentation of symmetrical hair loss.