Pinnae alopecia due to peripheral vascular dysfunction in three dogs

: We report three dogs with bilateral pinnal alopecia compatible with cutaneous vasculopathy. Case 1 was a 2-year-old castrated Jack Russell terrier with scaly alopecia since it was a puppy. Case 2 was an 8-year-old male Chihuahua presenting with progressive alopecia in the past one year. Case 3 was a 1-year-old miniature Dachshund that developed alopecia in winter. Infections and metabolic, cardiologic, and hematologic disorders were ruled out by clinical examinations and diagnostic tests. Administration of drugs to promote blood flow resulted in hair growth along with an increase in cutaneous temperature as confirmed by thermography and thermometer. The results suggest that peripheral blood circulation due to cutaneous vasculopathy could be involved in the pathogenesis of pinnae alopecia.