Poisonous plants and the natural toxins therefrom cause signiﬁcant economic losses to livestock industries throughout the world. Using 1989 ﬁgures, it was estimated that poisonous plants cause losses of over $340 million annually to the livestock industry in the seventeen western states of the U.S. (Nielsen and James, 1992; Frandsen and Boe, 1991). Applying a 3% annual inﬂation rate, this ﬁgure would have exceeded $500 million in 2003. This estimate only includes losses caused by the deaths of cattle and sheep and does not include increased management costs, lost forage and grazing opportunities, additional health care, etc. Other livestock species and wildlife are also aﬀected by poisonous plants, further increasing losses. As a recent illustration, in the spring of 1997 over 4000 calves either died or were destroyed because of lupineinduced ‘crooked calf syndrome’ in a single county of eastern Washington state (Panter et al., 1999). The direct losses to ranchers in this area exceeded $1.7 million (calf losses only). This ﬁgure did not take into account losses due to cow deaths, extensive culling of cows without calves, heifer replacement costs, increased cost of veterinary care, increased management, etc. Furthermore, this dollar amount does not take into account the economic impact on other businesses in the area supported by the cattle industry. The overall cost of poisonous plants to rural communities, and especially the livestock industry, is enormous.