Abstract. Spinal dysraphism, not associated with vertebral defect or arthrogryposis, was found in a 3-day-old Holstein-Friesian calf that was clinically diagnosed as having encephalopathy. The dysraphic lesion occurred in the sixth (C6) and seventh (C7) segments of the cervical spinal cord. Microscopically, the lesion was characterized by hydromyelia, syringomyelia, anomaly of the ventral median fissure, abnormal running of the myelinated nerve fibers in the white column, and absence of the central canal due to a developmental defect of the ependymal cells.Key words: Calf; dysraphism; histology; spinal cord.Spinal dysraphism, a congenital defect defined as a midline lesion due to incomplete closure of the neural tube, 1,4,10 is uncommon in cattle. 1 There are no recent descriptions of the pathology of this condition in cattle. This report describes an additional case of spinal dysraphism in a newborn calf.A 3-day-old Holstein-Friesian bull calf had been unable to rise since birth. The calf lay with the limbs and neck stiffly extended and showed sudden convulsive seizures at intervals of a few minutes. Paddling movements of the limbs were seen between spontaneous convulsions. The calf was euthanatized because of a suspected brain lesion with poor prognosis. The 4-year-old dam of the calf had given birth to another normal calf previously. Pedigree information about the sire was unavailable.At necropsy, the vertebral column, including cervical vertebrae, joints, and skeletal muscles, appeared normal; however, the C6 and C7 segments of the spinal cord had a centrally located spindloid cavity, measuring 1.2-cm long, 4 mm in diameter transversely, and 3.5 mm in diameter dorsoventrally at its maximum dimension. In addition, bilateral and roughly symmetric, smaller, cystic cavities filled with a clear fluid were in the dorsal septal region of the segment C7. Otherwise, there were no significant lesions.Microscopically, the central cavity at the C6 and C7 segments of the spinal cord was partially lined by ependymal cells, indicating its central canal origin; hence, the hydromyelia (Fig. 1). The central canal through C6 and C7 had a variety of abnormal features: a distorted canal lined by a single to double layer of ependymal cells, which showed variation in size and shape (Fig. 2); a dilated canal partially lined by pseudostratified ependymal cells whose nuclei were significantly smaller in size than those of the ependymal cells that lined the canal of the unaffected spinal segments (Fig. 3, Table 1); central microrosette formation (Fig. 4); and complete absence of the canal (Fig. 5), without evidence of preexisting inflammatory, traumatic, or neoplastic changes. The dorsal and ventral horn neurons appeared normal. In addition to the aberrations of the central canal, there were two cystic cavities in the dorsal funiculi, lined by parenchymal glial fibers; hence, the syringomyelia (Fig. 1). Dilated myelin sheaths with swollen axons or macrophages were scattered around the cavities. Proliferation of astrocytes was not foun...
Liver lactate dehydrogenase (LDH) isoenzymes in normal and diseased cows were analyzed electrophoretically. This method (histoelectrophoresis) was improved for the direct analysis of tissue LDH isoenzymes. The mean values of LDH 1 through LDH 5 in the livers of normal cows were 31.7, 24.8, 27.3, 12.8, and 3.3%, respectively. In cases with hydropic degeneration of the liver, the patterns revealed increases of LDH 1 and LDH 2 as compared to normal cows. The patterns showed a decrease of LDH 1 and an increase of LDH 2 in fatty change of the liver. Congestion of the liver alone decreased LDH 1 and increased LDH 3, LDH 4 and LDH 5. Necrosis of the liver decreased LDH 1 and LDH 2, and increased LDH 3, LDH 4 and LDH 5. It was suggested that the functional hepatocellular damage due to anoxia might be a important factor of the change of liver LDH isoenzyme patterns. We have attempted to standardize the LDH isoenzyme patterns by using a computer under various conditions. In cases with hydropic lesions, the diagnostic sensitivity (DS) was 53% (28 of 53 cases) and the predictive value of positive tests (PVPT) was 100% (28 cases of 28 cases selected). In cases with congestive or necrotic lesions, DS was 41% (9 of 22 cases) and PVPT was 69% (9 cases of 13 cases selected).
Twenty cattle (14 Holstein-Friesian, 3 Japanese Black, 3 Aberdeen Angus) ranging in age from 3 months to 8 years exhibited, at slaughter, emphysematous thickening of the ruminal submucosa owing to the appearance of numerous, contiguous, small gas bubbles. Microscopic changes in the ruminal submucosa consisted of (1) multiple cystic (emphysematous) lymphangiectasis that was frequently lined or occluded by granulomatous inflammatory infiltrates including macrophages, multinucleate giant cells, and eosinophils; (2) intralymphatic phagocytosis by macrophages and giant cells of eosinophils that showed positive labeling with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling assay; and (3) an inflammatory infiltrate extending from the area of lymphangitis into surrounding tissue, as well as edema, hemorrhage, fibrin exudation, fibroplasia, or capillary proliferation throughout the lesional submucosa. In addition, 15 (75%) of the cattle had globular leukocyte infiltrates in the mucosal epithelia of the rumen.
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