From April to August, 1985 on a swine farm in Akita Pref., diarrhea was observed in various groups of nursing piglets. During this period, 350 heads (3 to 20 days old) out of 435 Raised on the farm exhibited intermittent diarrhea ranging in color from white to gray. Themortality rate along with culling increased from 8.6 to 16.8% from about 5% during the normal period. Two diarrheal piglets were sacrificed for pathological, bacterological and virological examinations. At autopsy, a slight catarrhal lesion was observed in the small intestines, although no other gross lesions were found. Histopathologically, degeneration of the epithelial cells, coccidial infection of the epithelial cells and slight. infiltration of eosinophils in the lamina propria were observed in ileal lesions. Neither pathogenic bacteria nor viruses were isolated from these pigs. Parasitological fecal examinations were conducted in 4 piglets showing diarrhea in the same herd in addition to those 2 autopsied cases (6 in total), andIsospora suiswas isolated from 2 piglets. From these findings, it is considered that this incidence was associated withIsospora suis.
Tolazoline was studied at various doses to examine its effectiveness in antagonizing the xylazineinduced sedation in 45 cats. The cats were given a standard dosage of xylazine (2mg/kg; IM). Tolazoline was given IV at doses of 1 to 5mg/kg or IM at doses of 3 to 7mg/kg which reversed the sedative effects of xylazine. In addition, tolazoline at the above doses reduced or abolished bradycardia and hypothermia induced by xylazine. These effects of tolazoline were dose-dependent. However, tolazoline at a large dosage appeared to cause restlessness, piloerection and hyperemia. In cats given an overdosage of xylazine (5mg/kg; IM), tolazoline at dosages of 5mg/kg (IV) or 10 mg/kg (IM) also antagonized the sedative, bradycardic and hypothermic effects of xylazine. The results indicated that tolazoline can be clinically used as an effective antagonist to control the duration of xylazine-induced sedation in cats. For this purpose, it is suggested that tolazoline given IV at doses of 1 to 3mg/kg or IM at doses of 3 to 5mg/kg is suitable.
The dogs were vaccinated with different dosages of Canine Leptospira Bacterin (1 dose, 1/10 dose, and 1/100 dose) and then challenged to evaluate the efficacy of the Bacterin. Leptospira interrogans serovar icterohaemorrhagiea nd Leptospira interrogans serovar canicola were used as the challenge strains. Challenge inoculum was prepared from the livers of Leptospira-infected hamsters. Similar experiments were made on hamsters and guinea pigs, and their suitability as experimental animalswas evaluated. As a result, dogs vaccinated with 1 and 1/10 dosages of the bacterin did not show any symptoms when they were challenged. Whereas, the dogs with 1/100 doses developed some symptoms. All unvaccinated dogs died 4 to 6 days after the challenge. In the trials on experimental animals, hamsters showed a similar result to dogs. The hamsters vaccinated with the bacterin showed higher sensitivity to the challenge and had a higher agglutination titer than did theguinea pigs. Therefore, it is considered that hamsters are more suitable as an experimental animal for Canine Leptospira Bacterin as compared with guinea pigs.
The disinfecting activities of glutaraldehyde (GA) against several animal viruses were assessed by comparison with those of other disinfectants. The disinfecting activity of GA against rotavirus was analyzed at temperatures of 22 C and 37 C showing good results. At 4 C the disinfecting activity was poor. The presence of serum or tryptose phosphate broth as an organic substance in a viral suspension, had little affect on the virucidal activity of GA. GA efficiently inactivated rabies and parapox viruses and the capacity was comparable to that of sodium hypochlorite. In addition, it also had an inactivating capacity strongerthan that of sodium hypochlorite or iodophor against avian rotavirus and swine parvovirus, which were highly resistant to heat, various chemicals and pH. Moreover, its virucidal activity could persist for long periods of time even when diluted.
The fibrin thrombi in tissues, especially in the kidneys have been considered to be an important histopathological evidence of disseminated intravascular coagulation. However, the distribution of fibrin thrombi in the normal bovine kidney has not been elucidated. Thekidneys were collected from twenty-one seemingly healthy Holstein cattle at slaughterhouseand the Hokkaido Branch Laboratory, National Institute of Animal Health. The sections werestained with hematoxylin and eosin, phosphotungestic acid hematoxylin and immunohistochemical method. Fibrin thrombi were seen in the glomerular capillaries and in the renal interstitial vessels of all the cases. Fibrin thrombi were seen most frequently in the vasae rectae of the renal medulla.
On 5 farms, 49 calves naturally infected with gastrointestinal nematodes were treated witha single subcutaneous injection of ivermectin at 200μg/kg. In addition, 28 similar calves served as untreated infected controls. The anthelmintic efficacy was determined by their fecal egg count at I, 2 and 4 weeks after the treatment. Thc geometrical means of the fecal egg counts of Ostertagia, Oesophagostomum, Mecistocirrus and Trichuris were reduced bymore than 99%. However, only a slight reduction in the egg count of Nematodirus was observed. Among the 49 treated calves, 9 animals showed transient signs of irritation after the treatment.
The avidin-biotin-complex method was applied to the liver of 17 chickens experimentally infected with avian lymphoid leukosis (LL) for the investigation of cytoplasmic immunoglobulins (CIg). The liver having a few normal lymphocytes or plasma cells was used for this study. In the livers, the neoplastic cells showed a nodular growth pattern. A few CIgM-positive cells were observed in 3 cases. Both CIgM and CIgG were present in the cells of 12 cases. Thus not only these 2 classes but also CIgA was seen in the cells of 2 cases. Although most of the positive cells were large in size, smaller cells occasionally revealed positive reactions. Our study suggests that the heavy chain class switch may occur in the neoplastic cells of LL and that LL is closely related to lymphatic follicles
A 3-month-old Japanese black calf with sudden onset of recumbency and blindness was submitted for bacteriological, serological and pathological examinations. No significant results were obtained from serological tests for viral and bacterial infections. Microscopical examination revealed a widespread status spongiosus throughout the central nervous system, which was most prominent at the junctional areas of the gray and white matters. Each vacuoles was considered to be derived from either astrocytic swelling or intramyelinic edema. Similar lesions in the central nervous system have been reported in various hereditary diseases of calves including hereditary neuraxial edema. Thus, the present case was diagnosed as spongy degeneration of the central nervous system.
Percutaneous renal biopsies were carried out on 5 normal and 13 diseased cows. The side effects and diagnostic significance of this method were evaluated. 1) Macroscopic hematuria observed after the surgery in 18 cases disappeared within 90 minutes and microscopic hematuria disappeared within 180 minutes. 2) The sizes of the pieces of tissues obtained by the method were about 5-20mm long×1-1.5 mm width. Although they were slightly destryed and reduced in size, they were useful for diagnosing interstitial nephritis and amyloidosis. 3) In all 13 cases autopsied 1 to 10 days after biopsy, small, though not severe, hematomas were observed between the parenchymal tissue and capsules. 4) Abnormal findings due to the biopsy were not observed except hematuria mentioned above by the clinical and hematological examinations. From the results obtained, it may be suggested that percutaneous renal biopsy is a simple, safe and useful diagnostic method in the bovine practice.