Fall Panicum is a common annual warm season grass that can be hepatotoxic (cause liver disease) in horses under certain growing conditions. Toxicity in horses was documented in Virginia in 2004 when fourteen horses were diagnosed with liver disease as a result of consuming Fall Panicum hay. Currently, there have been several cases of suspected toxicity in horses grazing Fall Panicum in Northern Virginia pastures since late summer 2015. The trigger that causes toxicity and the amount of grass required to cause illness are not well understood, thus proper identification and treatment are essential for recovery.