Cold hemagglutinin disease in a toy Pinscher dog

High titers cold agglutinins were demonstrated in the serum of a 7 year old female toy Pinscher with a hemolytic anemia. In vitro, the serum did not show distinct hemolytic properties, but it fixed complement components to both the patient's own red cells and randomly sampled canine erythrocytes and agglutinated these cells at high dilutions at low temperatures (optimally at 0 degrees C). Serum electrophoresis on cellulose acetate membranes failed to reveal a paraproteinemia. Normal canine red cells sensitized with the patient's serum at 0 degrees C and eluted at 40 degrees C, released a cold agglutinin identifiable as IgM by immunoelectrophoresis. Neither IgA nor IgG were detectable in a concentrate of the eluate. The auto-antibody showed no specificity against the canine blood group A antigen and did not react with human O-erythrocytes, irrespective of whether these carried the I- or i-antigens. Following erroneous exposure of the dog to cold, cyanosis and serious gangrene developed at the acra (the ears, nose and feet). In addition, symptoms indicating diffuse intravascular coagulation were observed both hematologically and on pathological-anatomical examination. No primary disease could be demonstrated.