Technical Abstract: Endophyte (Neotyphodium coenophialum)-infected tall fescue (Lolium arundinaceum) occupies nearly 15 million ha in the USA. Although this symbiosis is beneficial to the plant, it produces ergot alkaloids that are detrimental to livestock production. Livestock consuming the alkaloids elicit adverse physiological responses including: elevated body temperature, reduced growth rates and reproduction, abnormal hair growth and shedding, and altered hormonal profiles. Several of these responses may be explained by alkaloid-induced vasoconstriction via interactions with biogenic amine receptors. Less is known concerning the toxicokinetics of the alkaloids. Existing literature suggests alkaloid metabolism occurs within the rumen, intestinal cells, and liver. Further, data suggest that clearance from the body is via urinary and fecal routes. Finally, there exists a need for a robust, selective and highly sensitive analytical method for alkaloid detection in animal tissues. This review provides an overview of ergot alkaloid mechanisms of action on the vasculature of livestock as well as the toxicokinetics and analyses.