Steroid-responsive cold-agglutinin disease with hematological and dermatological manifestations in a dog

An 8-year old, spayed female mixed-breed dog presented with necrotic, ulcerated lesions in the body extremities. Both pinnae showed extensive ulceration and necrosis with full-thickness fissures, extending horizontally through most of the pinnae. Crust-covered ulcerations, with variable degrees of necrosis and sero-sanguineous discharge were noted in the paw-pads, the dorsal aspect of the muzzle and the tail-tip. The mucous membranes were pale. A complete blood count revealed a regenerative anemia. Direct whole blood in-saline slide agglutination test showed mild agglutination (1 on a scale of 4) at room temperature, which was markedly increased (4 of 4) following a15-minute incubation at 4°C (39.2°F). Histopathology of biopsies from the pinnae, paw-pads and the muzzle demonstrated non-inflammatory, obliterative arteriopathy, with thrombosis, necrosis and exudative dermatitis. The acral distribution of the lesions, the histopathological findings and the accentuation of in-saline slide hemagglutination following cold incubation, were supportive of cold agglutinin disease (CAD). Imaging studies, biochemistry as well as serology and polymerase-chain reaction tests for endemic blood parasites were negative. Immunosuppressive prednisone treatment led to marked improvement of the skin lesions and resolution of in-saline slide agglutination and anemia. To the best of the authors’ knowledge, this is the first report of a favorable response to prednisone treatment in a dog with concurrent hematological and dermatological manifestations of CAD and the first report of CAD in Israel.