Kochia scoparia poisoning in cattle.

Cattle consuming only high-sulfate water (2.3 g/L) and Kochia scoparia in a marginal pasture in southeastern Colorado were periodically monitored by serum chemical profiles. Serum glutamic oxaloacetic transaminase, serum sorbitol dehydrogenase, and serum bilirubin values were abnormally high over extended periods, suggesting chronic toxicosis, but the toxicosis seemed accentuated after substantial rains, when plant growth was accelerated, and flowering, pollination, and early seed development were occurring. Clinical disease was manifested primarily as photosensitization. Polioencephalomalacia was also produced. Evidence of a thiamin-destructive principle in K scoparia was obtained.