Equine Fescue Toxicity

Equine fescue toxicosis is caused by the endophyte fungus Acremonium coenephialum, which infects tall fescue grass. According to the Cornell University Department of Animal Sciences, only broodmares and foals are adversely effected by equine fescue toxicosis.

  1. Tall Fescue

    • Tall fescue is a hardy cool season grass. Grown on an estimated 35 million acres in the United States alone, it's popularity is due to its high yield, resistance to drought and overgrazing and high quality nutrients.

    Broodmares

    • Broodmares that consume endophyte-infested fescue suffer from a range of reproductive problems including difficult birth, prolonged gestation, loss of the foal, thickened or retained placenta and agalactia (suppression of lactation).

    Foals

    • Newborn foals can suffer from abnormal growth, weakness, starvation, hyperthyroidism and poor immunity. Foals may be born with large size but poorly developed muscles as well as overgrown hooves and premature baby teeth.

    Treatment

    • Treatment consists of administration of the drugs reserpine, perhenazine or domperidone, which prevents agalactia.

    Prevention

    • To prevent equine fescue toxicosis, the grass must be eradicated and endophyte-free seeds replanted. Spray the pasture with herbicide in the late summer. Plant a winter annual grass or legume. Fertilize in late spring. Spray again with herbicide in the next late summer if necessary. Replant with endophyte-free seeds.