Peripheral arteriovenous malformation in a dog

Abstract

Arteriovenous malformation (AVM) is a circulatory alteration that can be described as an abnormal communication between an artery and vein. AVM is a snarled tangle of arteries and veins. They are connected to each other, with no capillaries between. That interferes with the blood circulation in an organ. An AVM leads to localized swelling, ischemia, and ulceration and possible compression of nervous tissue which contributes to pain. To date, in veterinary medicine, case reports of an AVM are rarely described. An 11 year old, mixed breed, spayed-female dog was presented with a swelling of left hindlimb. Physical examination revealed left hind limb edema but the gait appeared normal and without pain when palpated. A strong pulse of the saphenous vein was detected. Blood profiles and blood chemistry were within normal limits. Based on radiographs, soft tissue swelling was seen without radiographic evidence of skeleton abnormalities. Ultrasonography revealed that the femoral artery and femoral vein were enlarged. Computed tomography (CT) angiography revealed the vascular engorgement beginning from left external iliac artery and vein down to femoral artery and vein. The saphenous artery and the lateral saphenous vein were tortuous and engorged. Fluoroscopic angiography revealed a massive arteriovenous malformation and a venous varix was detected. Without surgical treatment, 3 months later, the dog started to develop pain and lameness. Consultation with human medical colleagues agreed that vascular correction was determined not to be possible. Limb amputation was performed to improve quality of life.