Ear edge vasculitis
Ear edge vasculitis is common in Chihuahuas and Dachshunds. "Punched out" lesions are usually present in the pinna, which
appear clinically as smudging of the pinnal vessels, resulting in alopecia and/or necrosis of the ear edges (Photo 5). Early
vascular smudging is evident when the lateral aspect of the pinna is backlit with an otoscope. Make the diagnosis by clinical
appearance, breed affected and skin biopsies.
Photo 5: Smudging of the pinnal vessels in a dog with vasculitis.
Fly strike and frostbite may occur in dogs housed outdoors. The distal pinnal tip is commonly affected, resulting in crusting,
ulceration and necrosis. Other conditions that more commonly affect the ear pinna than the ear edges include pemphigus foliaceus,
dermatomyositis, collagen disorders and cold agglutinin disease.
Although canine scabies is the most common differential diagnosis for ear edge changes, be sure to take the whole picture
into consideration. A thorough history, consideration of the breed affected and evaluation of any other clinical signs will
help in the diagnosis.
Dr. Jeromin is a pharmacist and veterinary dermatologist in private practice in Cleveland, Ohio. She is a 1989 graduate of The Ohio State
University College of Veterinary Medicine and an adjunct professor at Case Western Reserve University's College of Medicine