Fescue Toxicosis

By Dr. Kimberly Carr, DVM

With foaling season upon us it is important to discuss fescue grass and the negative impact it can have on late term gestation in broodmares. Fescue is commonly found in Oklahoma pastures and is known for being a durable, drought-resistant grass due to a symbiotic relationship with an endophytic fungus called Acremonium coenophialum (or Neotyphdium coenophialum). Research has found that more than 85 percent of Oklahoma’s fescue grass has been infected by this endophyte.

Unfortunately, there are no visual differences between regular fescue and infected fescue so horse owners cannot know if their mares are safe to continue grazing their pastures without further testing. Furthermore, there are no treatment regimens that will successfully remove the endophyte from the infected grass, so mare owners are best off if they remove the mares from infected pastures during the late stage of gestation.

To read more pick up a copy of the July 2020 NTFR issue. To subscribe call 940-872-5922.