Proliferative thrombovascular necrosis of the pinnae in a dog
The following are histopathological sections taken from the tips of the ear pinnae of a 5-year old male Labrador Retriever that presented with bilateral ulceration and necrosis of its ear tips. The dog is otherwise clinically well.
Final Diagnosis
Bilateral pinnal ulceration associated with chronic vascular thrombosis
Discussion
Histopathological and clinical findings are consistent with the syndrome known as proliferative thrombovascular necrosis of the pinnae. This is a relatively uncommon syndrome whereby thrombosis and/or proliferative changes within the small dermal arterioles result in ischaemic necrosis of the ear tips. Both ears are typically affected, however unilateral lesions may occur. The cause is currently unknown. Surgical resection of the affected tissue provides the best chance for diagnosis and clinical cure.