Between January 1998 and June 1999, on a certain dairy farm in Chiba Prefecture, 10 cows aborted. Examinations performed on 7 of them revealed 2 fetuses with subcutaneous edema, hyperemia or hemorrhage, and significantly increased serosanguinous fluids in the body cavities. The main histopathological lesions observed in the fetuses were purulent bronchopneumonia with bacterial clumps reacting positively when submitted to Gram's method. Bacterial clumps in purulent lesions were immunolabeled with anti-Arcanobacterium pyogenes serum. A. pyogenes was isolated purlely from the 2 fetuses already mentioned and from the uterus of another case. We have surveyed retrospectively 181 abnormal bovine parturition for the past 12 years-including the ones dealt with here-in Chiba Prefecture. Of them, 8 (4.4%) were diagnosed as infected with A. pyogenes. These abortions seemed to occur after the third gestation, frequently from spring to early summer.

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Clinical and pathological investigations were performed to determine the cause andpathogenesis of periarthritis in dairy cows. Lesion prevalence rate was 24.6%. Hind limbs were affected more frequently than forelimbs. Located on the dorsal sides of the carpal joints and on the external sides of the tarsal joints, lesions were characterized by abrasion, swelling, induration, fluctuation, and wounds. Cysts or abscesses in subcutaneous tissues were not connected with the articular cavity. Cyst exudate was obviously different in quality from synovial fluid. The CD4/CD8 ratio of mononuclears from peripheral blood isolated from cows affected with severe tarsal periarthritis was significantly higher than the corresponding ratio in healthy cows (P<0.05). The IgG1 concentration and the IgGl/IgG2 ratio in cows affected with severe tarsal periarthritis were significantly lower than those of healthy cows (P<0.05). On the basis of these findings, we concluded that the cysts had been induced by persistent or repeated physical pressure on the affected sites and that onset of periarthritis is closely related to dairy-cow management.

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Transmission of ryanodine-receptor mutant genes, which cause the porcine stress syndrome (PSS), was investigated in cases of 64 breeding boars on 12 general farms, 170 breeding sows on 11 general farms, and 294 pork pigs on 30 general farms. All farms are located in Toyama Prefecture. Perfarm, nearly 50% of breeding pigs were found to have heterozygous PSS genes. The corresponding per-animal rate was 8.5%. In the case of pork pigs, heterozygous PSS genes were found in animals from 11 farms and homozygous genes in animals from one farm. Heterozygous PSS genes were found in 6.1% of individual animals andhomozygous PSS genes in 0.7% of individual animals. All of the large-white strain of pigs raised at theToyama Prefecture Livestock Experiment Station were found to have normal genes. These results suggest that a cross between heterozygous PSS carrier breeding pigs occurs during pork production.

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Concurrent with investigations of living environment, age, origin, sex, breed, and examination season, we surveyed the prevalence of Otodectes cynotis in 679 household cats. O. cynotis was detected in 64 (9.4%) of the 679. Prevalence was significantly higher in cats kept outdoors (16.6%) than in cats kept indoors (8.3%, P<0.05) or cats keep both indoors and outdoors (4.6%, P<0.01). No significant differences in prevalence were noted with regard to age, origin, sex, breed, or examination season.

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A clearly demarcated nodule approximately 2 cm in diameter in the subcutis of a budgerigar (Melopsittacus undulates) was removed surgically and examined histopathologically. The thin capsule tissue surrounding central caseous necrotic debris contained polycentric micro-granulomas, vacuolar histiocytes, epithelioid cells, and degenerated connective tissue. Histiocytic micro-granulomas were located in or near dermis capillaries. Vacuolar histiocytes, epithelioid cells, and degenerated connective tissue occurred mixed within the capsule tissue. Pseudo-adipose tissue in the subcutaneous area consisted of these tissue components and was more damaged the farther inward they were located. Ziehl-Neelsen staining and immunohistochemistry revealed large numbers of acid-fast bacilli in the micro-granulomas and in degenerated pseudo-adipose tissue areas.

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Because of high serum levels of 17α-hydroxyprogesterone, two ferrets with bilateral symmetrical alopecia of the trunk were tentatively diagnosed as having hyperadrenocorticism. Abdominal computed tomography revealed no obvious adrenal enlargement in either animal. In case 1, treatment with danazol followed by cyproterone acetate produced no fur recovery. Histopathological examinations revealed adrenocortical carcinoma in both animals. In about a month and a half after tumid left adrenal resection, both ferrets' fur had completely recovered. The animals continue in good condition at the present. In case 1, serum 17 α-hydroxyprogesterone has dropped to the normal range.

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