Japanese Journal of Veterinary Research;Volume 5, Number 2

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STUDIES ON INFECTIOUS CANINE HEPATITIS I. : HISTOPATHOLOGICAL STUDIES ON SPONTANEOUS CASES

FUJIMOTO, Yutaka

Permalink : http://hdl.handle.net/2115/1707
JaLCDOI : 10.14943/jjvr.5.2.51

Abstract

The author from the histopathological approach investigated a total of 14 spontaneous cases of H.c.c., including cases in foxes. In the postmortem material rendered available in this laboratory during the period 1951〜1955,H.c.c. has occurred in 5.32% of the cases (14/263). All cases which showed acute or subacute lethal course were investigated. The duration of the disease was 2〜14 days, generally a 2〜4 day rapid course. In the postmortem picture of H.c.c., circulatory disturbances play the leading part in the disease. Edema and hemorrages were usually conspicuous. The former was found in the wall of the gall-bladder, the pancreas, the portal root and the portal lymph nodes : in the abdominal cavity sero-hemorrhagic exudation was often present. Edema was often seen in the subcutaneous tissue and the tissue around the body lymph nodes. The thymus and pericardiac mediastinum usually showed a remarkable edema. The latter regularly occurred in almost all parts of the body. On the other hand, acute parenchymatous hepatitis, acute fibrinous perihepatitis, enlargement of the spleen, tonsillitis, lymphadenitis, congestive edema in the lungs, occasional catarrhal bronchitis or bronchopneumonia, and hemorrhagic gastroenteritis were observed. Histopathologically, the changes caused by the disease are classified as follows : 1) Parenchymal degeneration, such as centrolobular hepatic necrosis, nephrosis, necrobiotic and necrotic foci in the various organs, 2) Activity of reticulo-endothelial system, 3) Circulatory disturbances, such as edema, hyperemia and hemorrhages. 4) Characteristic nuclear inclusions (containing DNA and RNA) occur in various cells in almost all the germinal layers. Eosinophilic necrosis in the liver is not pathognomonic, but it is a characteristic finding of the disease. This change is observed at any stage of the disease, but especially it seems to occur in the early stage. Regressive parts of the liver showed decrease or disappearance in PNA. On the contrary, the cytoplasm of reticulo-endothelial cells in sinusoids are rich in PNA. Fatty degeneration of liver and kidneys is not a characteristic finding of the disease. Despite an apparently severe destruction of the liver cells, the reticular fibers of the liver are found to be intact, but in some cases the argentophil character has been partially lost. Proliferation and thickness of the fibers were not observed. Icterus is not always characteristic of the disease. In one case, the author observed mixed infection of toxoplasma (No.9). The changes in the central nervous system were not encephalitic changes In fox cases, in spite of the manifestation of marked encephalitic symptoms, histological pictures showed no essential differences from dog cases.

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