ABSTRACT. We present a clinical overview of a dog with acute onset of Hepatozoon canis infection. A stray female beagle dog of unknown age was referred to Kagoshima University showing anemia. Blood tests revealed the presence of anemia, thrombocytopenia, hyperproteinemia, polyclonal gammopathy, hypoalbuminemia, and elevated creatine kinase and alkaline phosphatase activities. In addition, capsule-like organisms were detected in the cytoplasm of approximately 50% of neutrophils in blood smears. H. canis infection was confirmed by polymerase chain reaction and DNA sequencing analyses. Amplified DNA fragments revealed 100% identity to the 18S ribosomal RNA gene of H. canis. The clinical symptoms improved after the administration of antibiotics. Hepatozoonosis in dogs is rare, but veterinarians should be alert to its possible acute onset. Hepatozoon is a genus of protozoa belonging to phylum Apicomplexa. Dogs are known to be susceptible to infection by both Hepatozoon canis and H. americanum, but only the former has been confirmed in Japan [3,10,[15][16][17][18][19]21]. Hepatozoon parasites are transmitted by ticks, and the infection becomes established after the ingestion of infected ticks [4]. Ingested parasites enter the blood or lymphatic vessels through the intestinal mucosa and reach the bone marrow. Most H. canis infected dogs show clinical latency, and several factors, such as co-infection with other infectious agents and immunosuppression, are thought to be important factors promoting the acute onset of hepatozoonosis [2,4,6,9,20]. A few reports have described the acute onset of H. canis infection and its epidemiological distribution in Japan [10,[15][16][17][18][19]. The clinical symptoms associated with severe H. canis infection are anemia, fever, lethargy and weight loss [5]. Ataxia and lameness are also sometimes observed in Hepatozoon-infected dogs, due to the development of osteomyelitis. Characteristic hematological abnormalities in H. canis infection include non-regenerative anemia, thrombocytopenia, neutrophilia, hyperproteinemia, hypoalbuminemia, polyclonal gammopathy, and increased serum creatine kinase (CK) and alkaline phosphatase (ALP) concentrations [5][6][7]. The detection of capsule-like gamonts in the cytoplasm of neutrophils in blood smears is helpful for diagnosing hepatozoonosis. Other diagnostic techniques, such as polymerase chain reaction (PCR) for Hepatozoonderived genomic DNA or enzyme linked immunosorbent assay for anti-Hepatozoon antibodies, are also potentially useful [8,10,11] A stray female beagle dog of unknown age was cared for by a temporary owner in the suburbs of Kagoshima, Japan. The owner took her to a private veterinary hospital for a health check. Severe dehydration, numerous ticks on the skin and pale mucus membranes were detected by physical examination (day 1). Fecal examination revealed roundworm, whipworm and tapeworm infections. Blood examination demonstrated the presence of anemia [packed cell volume (PCV), 17%], leukocytosis (44,900/l) and mild thrombocytopen...

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.