We know that contaminated feed can cause serious problems for horses, ranging from colic and cardiac problems to neurologic issues and death. For instance, researchers recently documented a case in which feed contaminated with trichothecene mycotoxins caused signs of bone marrow cell proliferation suppression, severe bleeding, and hair loss in horses that consumed it.

During a presentation at the 2015 American College of Veterinary Internal Medicine Forum, held June 4-6 in Indianapolis, Indiana, Rachel Liepman, DVM, a resident in internal medicine at The Ohio State University Veterinary Medical Center, shared what she and colleagues recently learned about trichothecene ingestion’s impact on four American Quarter Horses.

Liepman said the index case—an 11-year-old mare—presented to a clinic with lethargy, acute perineal edema (fluid swelling in the perineal area, beneath the tail), hematochezia (bloody stools), fever, patchy alopecia (hair loss), and petechiation (small purple spots on mucous membranes). The mare’s bloodwork showed severe panleukopenia (a decreased white blood cell count), thrombocytopenia (decreased numbers of circulating blood platelets), and a prolonged prothrombin time (how long it takes blood to clot). Additionally, when veterinarians evaluated her bone marrow, they found profound myeloid hypoplasia (decreased white blood cell production) and megakaryocytic hypoplasia (decreased production of megakaryocytes, which produce platelets), Liepman said.

In collecting the mare’s history, Liepman said the veterinarians learned that she, along with other horses, had recently received a new batch of hay. This initially caused feed aversion and later some drooling, she said, and the team further learned that the hay had been improperly cured (dried) during production