Chronic myelogenous leukaemia with persistent neutrophilia, eosinophilia and basophilia in a cat.

Chronic myelogenous leukaemia was diagnosed in a 7-year-old male neutered domestic shorthair cat. Leukocytosis (74,900/µl)--mature neutrophilia, eosinophilia and basophilia--was observed. Bone marrow aspiration revealed hypercellularity with proliferation of cells of myeloid lineage. An underlying condition leading to leukocytosis was not identified. The severe leukocytosis did not respond to antibiotic therapy. Based on these findings, chronic myelogenous leukaemia was diagnosed. Because of the absence of clinical signs, the cat was monitored without treatment until 7 months after diagnosis, when it developed pruritic skin lesions. Pruritus was controlled with oral prednisolone. Forty-two months after diagnosis, the cat developed nasal lymphoma, which was treated with radiation therapy, resulting in complete remission. The cat was still in good physical condition 63 months after diagnosis, despite the persistence of marked neutrophilia, eosinophilia and basophilia.