Moldy sweet clover (dicoumarol) poisoning in Saskatchewan cattle.

Information pertaining to 286 animals from 56 herds affected by moldy sweet clover poisoning in Saskatchewan during 1983 was tabulated from the toxicology laboratory records. The morbidity in the affected herds was 12.1%, with a case fatality of 65.5%. Aborted fetuses and calves less than two weeks of age were affected with sweet clover poisoning most often. Sweet clover poisoning was more common during the period from January to April, 91.6% of the morbid animals were seen at this time. The rates of poisoning in beef and dairy cattle were estimated to be 0.156 and 0.095 cases per 1000 cattle respectively. Sweet clover poisoning was observed with the use of large of small bales of sweet clover in 78.9% of the affected herds. The geographical distribution of sweet clover poisoning in Saskatchewan followed the northern regions of the dark brown soil zone and the southern regions of the black soil zone which extend from the mid northwest portion of the province to the extreme southeast region.Dicoumarol concentrations were determined on a variety of tissues including liver, plasma, serum, kidney and muscle. Significant differences in the liver dicoumarol concentrations were found between animals of different ages (P = 0.045). Livers from younger animals, in particular, the fetus, contained lower concentrations of dicoumarol.