Calf diarrhea model was established, then pathophysiological changes and therapeutical method in early stage of diarrhea were studied with this model. Heat stable enterotoxin produced by E.coli was purified and its activity was determined as mouse unit (MU) by suckling mouse method. STV was expressed production of inocu-lated volume per body weight (kg) and MU. Required STV for induced diarrhea with dehydration was 11, 200. Hematocrit and serum Na concentration indicate that blood was concentrated and electrolytes were lost. Two hours after ST inoculation oral treatment was done. Oral electrolyte administration decreased hematocrit and increased serum Na concetration, indicating water and electrolyte were absorbed. After milk replacer administration blood glucose was increased but rehydration was not observed. Lukewarm water was inadequate for oral treatment, because hemoglobinurea was observed 2 hours after treatment.

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We recieved bovine Escherichia coli bacterin (ABAH, USA) containing formalin-killed whole cells of K99 positive enterotoxigenic E. coli (ETEC) and its seed strain. First, serological properties, ability of toxin production and plasmid nature of this strain were examined. Next, a new method for measuring K99 antibody titers was examined. Then immunogenicity test of this vaccine was performed. In addition to the above mentioned studies, epidemiological survey on field outbreaks of bovine ETEC infection in Japan were carried out. The seed strain NADC1471 was sho-wn to harbor four stable plasmids. The 67-Md plasmid was proved to be associated with production of K99 antigen and STa. The serotype of this strain was identified to be 0101, K99, F41 and enterotoxin produced to be STa. This antigenic formulation corresponded with the dominant serotype recovered from diarrheal calves in Japan, proving this strain to be a desirable one as a vaccine strain. Passive hemagglutination (PHA) test for measuring K99 antibody titers was established to evaluate antigencity of the vaccine. The comparative studies between bacterial agglutination test and PHA test revealed good correlation (r=0.879) in anti-K99 titers. Higher antibody geometric mean titers (about 2.5 fold) were obtained with PHA test which were employed to evaluate the efficacy of the vaccine. In the immunogenicity study, calves from cows vaccinated twice were employed as the vaccinates, and calves nursed with milk contai-ning no K99 antibody were employed as the controls. At the 12th hour of birth after the ingestion of sufficient amount of colostrum, both groups were challenged with virulent ETEC for evaluating the protective efficacy of the vaccine. After challenge all of the vaccinates survived and controls developed severe persistent watery diarrhea resulting in death. From these findings, successful maternal protection via colostrum was proved. In the epidemiological survey E. coli strains obtained from rectal swabs of 270 calves with diarrhea were examined. The rectal swabs were collected nationwide (21 prefectures) and their age were distributed to be 1 to 30 days old. E. coli strains detected from 33 calves (12.2%) were idenified to be ETEC. And 29 (87.9 %) among these 33 calves positive for ETEC developed watery diarrhea when they were less than 5 days of age. This epidemiological findings concerning bovine ETEC infection is in accord with those in foreign countries, proving the intimate participation of ETEC in calf diarrhea.

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The test horses were 266 cases of race-horses which have been available for the racing at Kaminoyama Race Track, Yamagata Prefecture for 3 years from 1991 to 1993. The test horses used in the first experiment were 112 cases of race-horses which have been available for the racing in 1991. The author examined the effects of 3 kinds of laser apparatus on locomotorial diseases including muscle sore, under laser irradiating conditions of 180, 60 and 60 sec. irradiating time at 80, 150 and 500 mW outputs, respectively. Test horses used in the second experiment were 154 cases of racehorses which have been available for the racing in 1992 and 1993. The author examined both the effects of 2 kinds of laser apparatus and their pain-relief mechanism, under laser irradiating conditions of 30 and 20 sec. irradiating time at 150 and 500 mW outputs, respectively. Laser irradiation was remarkably effective (68.2%) and effective (27.6%) on 163 and 66 of 239 muscle sore cases, respectively, with an effectiveness rate being 95.8%. Irradiation times at outputs 150 and 500 mW were shortened from 60 to 30 and 20 sec., respectively. The remarkable effectiveness rates for myalgic cases were low, but effectiveness rates were high in either case. Laser irradiation led to a significant (p<0.01) decrease in the degree of myotonia. Laser irradiation led to significant decrease in Ht and WBC, suggesting a normalized sympathetic nerves induced effect. PGE₂ showed a significant (p<0.05) decrease immediately after irradiation. PGE₂ was shown to be significantly (p<0.05) decreased for normal horses compared with muscle sore horses. PGE₂ was significantly (p<0.05) decreased for cases of effective laser irradiation both immediately after and one hour after irradiation. β-endorphin was somewhat increased immediately after laser irradiation, but without a significant difference.
The above results suggest laser irradiation to be very effective on muscle sore of race-horses. The significant decrease in. PGE₂ was shown to be correlated with the pain-relief from muscle sore.

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A calcium preparation (Ca) was injected into the cow i.v. two days after a parturition and mainly uterine involution was investigated by an ultrasonic image. 23 Holstein cows in the F and M meadows with different breeding conditions were used in this test. The experiment group, six cows in the F meadow (F) and nine cows in the M meadoe (M) was injected with a Ca and a control group was done with glucose. 1) The time to dispose of the lochia in the uterine horns was 24.8 and 32.8 days in the F meadow, and 25.1 and 38.0 days in the M on the average, respectively. 2 ) The time until the shape of the uterine horns was judged to be recovered was 19.5 and 20.5 days on the average in the F meadow, and 15.1 and 22.5 days in the M meadow. The time until elasticity was judged to be recovered was 20.3 and 19.8 days on the average in the F meadow, and 15.3 and 22.5 days in the M meadow. 3 ) The uterine involution time in the ultrasonic image was 35.5 and 41.5 days in the F meadow, and 30.1 and 44.0 days in the M meadow, on the average. 4 ) The average time required until the first postpartum ovulation occurred was 34.0 and 40.8 days respectively in the F meadow and 24.2 and 47.5 days in the M meadow. These results suggest that the intravenous injection with a Ca preparation immediately after the parturition might have an effect to shorten the time required for uterine involution and first ovulation.

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Sawdust Liver is found in 20 of 199 fattened Japanese Black cattle. The cattle were fed in two feeding patterns, with the incidence of Sawdust liver being 23.4% in A fodder group (A group) and 3.7% in B fodder group (B group), and it was admitted to be a significant difference in the incidence rate between the two groups. By necropsy, a yellowish-grey foci and a darkred foci, ranging in size from minute to 3mm in diameter, were scattered on the surface and within the liver. Finding of the yellowish-grey foci type was 40%, finding of the dark red foci type was 15% and finding both foci types was 45%. We found lesions in the liver which was the focus of necrosis within the lobules hepatis, and hyaline bodies appeared in the cytoplasm, there was a changed pyknosis, rhexis and lysis of the nucleus, and infiltration of leukocytes also appeared. We found at the same time dilation and congestion of the sinusoids. We could not find significant difference in the internal organs such as the spleen, kidney, heart and lung. We could not find growth of bacteria. We did a hamatological comparison between cases with Sawdust Liver and normals. There were cases with significant differences, in GOT, levels and in Se levels. In addition, We found significant differences in each, the A group is 29.7mU/ml and the B group is 26.4mU/ml with γ-GTP, 114. 6mg/dl and 106.2mg/dl with Cholesterol, 2.13μg/ml and 1.85, μg/ml with vitamin E. These results suggest that a cause of the Sawdust Liver my be related to food, because the apparent diffrence between A and B, is the generation.

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We epidemiologically investigated L. C. taxia whidis, of unknown cause and increase with time in sika deer (Cervus nippon hortulorum Swinhoe), on a from of sika deer in China. The early findings showed an unsteady posterior body, an ab-normality in gait, and bristles and discoloration of the body hair. The terminal findings showed a seated posture resembling that of a dog and paralysis of the posterior body. The consciousness of the animal was clear until its death. From these findings L. C .pinal diseases were suspected. Since the first occurrence in 1985, ataxia has tended to increase gradually. In April 1990, the disease was present in 134 (9.3%) out of 1, 434 deer. It developed in sika deer aged 2 years or older regardless of season, and there was no statistically significant difference in incidence between stags and does. The development of ataxia was investigated in terms hereditary background, structure of the facility, hygenic environment and the food supplied, but no active causal relationships were found.

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