Arteriovenous Malformation of the Tongue Resulting in Recurrent Severe Hemorrhage in a Young Dog.

An 8 mo old male entire beagle was presented to the emergency and critical care service following several severe bleeding episodes from the oral cavity. Oral examination revealed a purple, spongy, pulsatile lesion on the rostral two-thirds of the tongue. Computed tomography angiography revealed a severely distended right linguofacial vein with numerous, tortuous branching vessels within the tongue, consistent with an arteriovenous (AV) malformation. A cervical surgical approach was performed, and the right lingual artery was isolated and catheterized. A direct arteriogram confirmed this was the main feeder artery to the lesion, and it was ligated. Although the bleeding episodes initially resolved, a moderate bleeding episode occurred 6 days postoperatively, and a partial glossectomy was performed. Histopathology was consistent with an AV malformation. The dog had a good recovery from surgery and remains free of clinical signs 13 mo later. Following extensive review of the veterinary literature, this is the only reported case of a lingual AV malformation in the dog. Partial glossectomy resulted in resolution of the clinical signs and was well tolerated. Although rare, AV malformations should be considered as a differential diagnosis for spontaneous oropharyngeal bleeding.