1. The fasciolicidal effect of tetrachlorodifluoroethane (TDE) was confirmed in four rabbits which were given, 71 days after artificial infection, 250, 500, 750, and 1, 000mg, respectively, of TDE per kg of body weight, with no apparent side effect. 2. Fasciolicidal effect was shown in all four sheep and two goats which received, by stomach tube, 150 to 400mg/kg of TDE, without apparent side effect. A goat showed the same efficacy when it was administered with 800mg/kg of TDE into the rumen, although it manifested transient unsteady gait and anorexia. In addition, a dose of 300mg/kg showed killing effect on stomach flukes in a sheep. 3. Six sheep and two goats having received a dose of 100 to 400mg/kg by stomach tube showed markedly reduced egg counts within 30 days after medication, the reduction rate being 98.4 to 100 per cent. The side effect was very slight. 4. Remarkably reduced egg counts and necrosis or removal of parasitic flukes were confirmed in six Japanese oxen and one dairy cow all receiving a dose of 50 to 200mg/kg by stomach tube or drenching. The killing effect of TDE, however, seemed to be unsatisfactory on relatively young flukes. No side effect was observed in either case. 5. When doses ranging from 10 to 300mg/kg of TDE were used in 48 dairy cows and a Japanese ox, a dose of 40mg/kg or more was effective to bring about a reduced or negative egg output. When changes in egg counts were examined, a reduced egg output and a negative egg output were observed in 1 and 2 cows, respectively, of 5 receiving 40mg/kg, each 1 of 4 receiving 50mg/kg, 5 and 4, respectively, of 10 receiving 100mg /kg, each 7 of 17 receiving 200mg/kg, and 0 and 3, respectively, of 5 receiving300mg/kg. Administration by the stomach tube seemed to bring better results than that by drenching. In addition, a dose of 200mg/kg or more caused markedly reduced egg counts of stomach flukes. Side effect was slight. Reduction in milk yield was but transient. No abnormality was found in pregnant cows. 6. From these results, a dose of 300mg/kg of TDE is recommended for the removal of liver flukes of sheep. For cattle it is recommended to use 100 and 200mg/kg of TDE against liver flukes and stomach flukes, respectively.
Coagulase-positive staphylococci (cps) were detected during the process of powdered milk production in three plants in Hokkaido. Isolated stra ins were classified into phage types. It was confirmed that contamination with CPS during tne manufacturing process was the secondary contamination of the balance tank of concentrated milk. Potential sources of contamination were presumed to be straining cloth and a mixture of dust in the air and scattered particles of powdered milk containing CPS. Such mixture seemed to enter the balance tahk directly or through the intermediary of workers. Part of the CPS thus mixed with concentrated milk multiplied in a hollow portion of the pump equipped in the drier for pushing the milk forward. It was made clear that CPS invaded the powdered milk in this manner.
Dogs inoculated with chick-embryo-adapted live distemper virus vaccine was involved in spontaneous apparent infection of distemper. Clinically, they manifested fever of two-peak type, depression, inappetence, discharge from the eyes and nose, coughing, and sneezing. Pathologically, they exhibited degenerative and hyperplastic changes of lymphatic reticular tissue, broncho-pneumonia, catarrh of the digestive tract, activation of the reticulo-endothelial system in various organs, and encephalitis, although there were variations among them. In addition, cytoplasmic and nuclear inclusion bodies were present in epithelial cells of the bronchi, pulmonary alveoli, urinary bladder, pelvis of the kidney, biliary ducts, pancreatic ducts, and alimentary canal, as well as the glandular cells of the pancreas and neuroglia cells. Moreover, demonstration of virus was positive in the brain, liver, and spleen of a hamster inocula.- ted with infected material. Detection of neutralizing antibody was also positive. As a result, a positive diagnosis of distemper was made in these vaccinated dogs. Furthermore, the source of supply of these dogs involved and the results of virological studies on them made it possible to assume that the etiological virus had not been derived from the chickembryo- adapted vaccine inoculated but was “street” virus which had infected the dogs before they received the vaccine. Some discussion was additionally made on the risk which would be met in inoculation experiments with dogs of unknown origin of supply and in inoculation of such dogs with live vaccine.