Cutaneous vasculitis refers to inflammation of the blood vessels in the skin (Figure 1) that results in altered blood flow and ischemic necrosis of the skin (Figure 2). The condition may be idiopathic or caused by adverse drug reaction, infection, insect bite, or neoplasia.Treatment should address the underlying cause and repair tissue damage. Pentoxifylline is an ideal treatment (regardless of cause) because of its effect on perfusion and inflammation. Because pentoxifylline has a potential delayed onset of effect, it is often combined with other drugs (eg, glucocorticoids). In a retrospective study, 9 of 19 dogs with vasculitis were treated with pentoxifylline (10-20 mg/kg PO every 12 hours) alone (1 dog) or in combination (8 dogs) with prednisone (1.5-3 mg/kg/day) with variable success. Six dogs had complete resolution, 2 had partial resolution, and 1 failed to respond. Of the 6 dogs with complete resolution, 3 relapsed when prednisone was tapered, suggesting that pentoxifylline may be insufficient when used alone to treat vasculitis.Insufficient dosage and frequency could explain the limited success and lack of response in 3 dogs.Despite reports of variable success, pentoxifylline is often used for the treatment of vasculitis.