A bleeding disorder (von Willebrand's disease) in a Himalayan cat.

A bleeding disorder (von Willebrand's disease) was diagnosed in a 9-year-old male Himalayan cat examined because of persistent oral bleeding after routine dental extraction. Bleeding subsided after empirical treatment, which included prednisolone, vitamin K1, and transfusion of fresh blood, but recurred spontaneously after 8 months of apparent good health. Pertinent results of routine laboratory testing included an inconstant prolongation of the activated partial thromboplastin time and recurring iron-deficiency anemia. Assays of specific coagulation factors revealed low factor VIII coagulant activity and undetectable factor VIII-related antigen, a pattern considered to be diagnostic of von Willebrand's disease. This condition, not previously reported in a cat, should be included in the differential diagnosis when cats are examined because of abnormal bleeding.