Experimental sulfur toxicosis in sheep II- pathologic evaluation of neural and extraneural lesions

Two equal groups, 3 of each, of adult female Balady sheep [8-9 months old] were fed a balanced diet with or without elemental sulfur [0.8% in diet] up to the appearance of neurologic signs including coma and animals were going to die [days 25, 26 and 28 of the experiments for the three intoxicated sheep, respectively]. Brain lesions were typical of polioencephalomalacia primarily of the neocortex and to less extent the cerebellar grey matter. The nonneural lesions included constant severe, diffuse periportal necrosis with centrilobular degeneration, pulmonary edema complicated into serofibrinous pneumonia because of germ invaders, nephrotoxic tubulonecrosis with tubular casts, cardiomyocyte degeneration and segmental necrosis as well as lymphocytic cell depletion of spleen white pulps. Both the gastrointestinal tract and skeletal muscles had no lesions. It could be concluded that the noticeable hepatic lesions may augment the toxic effect of dietary sulfur because of impairment of the hepatic detoxification system to the liberated toxic sulfide ions in the rumen

Pathologic studies on the sublethal effects of phenol on grass carp [ctenopharyngodon idella]

The pathological effect of long-term exposure to pure phenol was studied in grass carp. The highest level of phenol which could be tolerated by carp was 15 ppm. At this concentration, the associated clinical signs were nervous in their nature, began as excitation and ended by depression. The gross lesions were color changes of the skin, increased mucous secretion from gills and hyperemia of the viscera, especially of the brain. The histopathologic findings were degenerative and necrotic changes in gills, muscles, spleen, kidneys, liver, heart and brain which, by time, became less evident or absent. The clinical signs and lesions disappeared after the transfer of the affected fish to clean water