Phenylbutazone-induced blood dyscrasias suspected in three dogs

Blood dyscrasias developed after drug therapy in three dogs. Two died, one with pancytopenic marrow failure and the other with non-regenerative anaemia and thrombocytopenia. The third dog developed pancytopenia but recovered. An adverse reaction to phenylbutazone was suspected as the cause in each case, although two of the dogs had also received other drugs which sometimes cause blood dyscrasias in humans.