Some organisms that infect grass prove harmful to horses. When the mare in the case was pregnant, the owners had the pasture with tall fescue grass tested. Fescue can contain an endophytic fungus that produces ergot alkaloids that are chemically similar to neurotransmitters (Browning, 2003). These alkaloids can interfere with the physiological control of labor and delivery as well as the survival of the foal. Should a pregnant mare be removed from a pasture infected with this fungus and fed solely supplemental feed?