Pathological features of osmose poisoning in a cow. neuropathological observation

A one-year-old crossbred-Holstein which died, about 4 days after the onset of symp-torus, of osmose poisoning was histopathologically investigated from a general viewpoiratwith special consideration of neuropathology. A complementary experiment was carriedout in mice orally administered with osmose.Taking changes almost common to both cow and mice into consideration, the prin-cipal changes seen in the cow were classified as follows: (1) multiple hemorrhages ex-tended over the whole body, (2) microvascular alteration (in other words, edematousloosening and swelling of the walls of small blood vessels), (3) polyneuropathy, (4) cere-brat edema and degeneration of nerve cells in the central nervous system, (5) fattydegeneration of the liver and edema of the gall bladder, (6) destruction (karyorrhexis)of lymphocytes in the lymphoid organs, (7) ulceration in the forestomach and abomasum, and (8) decrease in number of cellular elements in the bone marrow.Chemical and histochemical examinations for detection of arsenic and fluorinefailed to give positive results in both cow and mice.The following pathological features were inferred as "predisposing changes" inthe morphological sense: (l) a considerable part of the process of nervous disturbances(polyneuropathy), (2) a considerable part of the process of microvascular alteration, and(3) a part of the ulceration in the forestomach and abomasum and a part of the myo-pathic process in the striated and smooth muscles.The idea "predisposing changes" may give a certain suggestion for the interpreta-tion of pathological features in naturally occurring cases of various types of poisoning.