Monocytic leukemia in three cats.

Of 3 cats with monocytic leukemia, 1 responded favorably to treatment with cytosine arabinoside. With supportive therapy, it lived 78 days from the time of diagnosis, at which time it developed dyspnea and signs of toxicosis and died. The other 2 cats did not respond to treatment and died 4 and 16 days from time of diagnosis. Prior to death, they were bleeding from injection sites, and their blood had greater than 200,000 WBC/mm3. Necropsy of those 2 cats revealed extensive perivascular hemorrhagic infarcts within the cerebellum, medulla, and cerebrum.