Utilization of an enzyme heat stability test and erythrocyte glycolytic intermediate assays to assist in the diagnosis of canine pyruvate kinase deficiency.

A macrocytic hypochromic anemia, with marked reliculocytosis and large numbers of circulating nucleated erythrocytes, was recognized in a 3 1/2-year-old male Beagle-cross dog. A presumptive diagnosis of erythrocyte pyruvate kinase (PK) deficiency was made, even though PK activity from the patient was within the range of activities measured for normal dogs, because the PK activity should have been several times normal in light of the large number of reticulocytes present. The PK activity in a hemolysate from the patient was heat-labile compared to activities in hemolysates from normal dogs, a finding consistent with results from a previous study of PK-deficient Basenji dogs.