Raised with experimental cats in the same room, a 4-month-old puppy suffered suddenly from emesis, bloody diarrhea, and intense leukopenia, and died 3 days after the onset of disease. Histopathological examination revealed extensive necrosis and desquamation of the mucosal epithelia, and hemorrhage in the muous cmembrane of the small and large intestines, a decrease in number of hematopoietic cells of the bone marrow, and marked atrophy of the splenic follicles. A virus was isolated from the kidney. It had formed large intranuclear inclusion bodies in fibroblasts of the feline lung. It was identified as parvovirus from its serological and biological properties. Cats and dogs kept in the same room with the dead puppy manifested a high HI antibody titer. When inoculated orally with the isolated virus, healthy dogs or cats showed no signs, except mild leukopenia.
The mouthparts of tabanid flies, including Tabanus nipponicus, which had sucked blood from leukemic cattle, were examined by scanning electron microscopy. Many (about 2, 000) lymphocytes were observed in the mandible and maxilla, which cut through the integument of cattle. Salivary ducts, mesentery, malpighian tubules and ovary of flies having sucked blood were observed by transmission electron microscopy 24, 48, and 120 hours after blood sucking. No virus-like particles were found in any organ. Therefore, it was suggested that tabanid flies might mechanically transmit white blood cells with bovine leukemia virus from infected animals to new hosts.
A diagnosis of mast cell tumor was made in a three-year-old female cat with marked abdominalIdisten. sion and anemia on the basis of splenomegaly, hepatomegaly, and the appearance of mast cells both in peri. pheral blood and in bone marrow. The animal was put under a series of cancer chemotherapy and well maintained for over one year. The chemotherapy was initiated with prednisolone (1.5mg/kg/day) alone for 2 months, which was followed by cyclophosphamide (2mg/kg/day) and vincristine (0.05mg/kg/2 weeks) for 3 months. Then small doses of prednisolone and cyclophosphamide were administered continually. Since no serious side effects. were found, the combination of the three drugs was highly evaluated as a reliable therapy against feline mast cell tumor.