Horse owners everywhere take extreme measures to be sure their animals are safe from harm. But did you know that your horse might be ingesting toxins on a daily basis? Reports from Dairyland Laboratories and the Iowa State Veterinary Diagnostics Laboratory indicate that levels of molds and mycotoxins (toxins produced by molds and other fungi), particularly a toxin called deoxyvalenol (DON), produced by Fusarium mold, are rising in crops harvested in 2009 (a wet year with ideal conditions for mold growth). Livestock producers across the United States are taking steps to minimize feed contamination, such as drying corn, adding propionic acid (a mold inhibitor) to stored grains, and inoculating their silages and haylages. Horse owners can employ these and other methods to reduce the risk of mycotoxins.

What are mycotoxins?

Mycotoxins are harmful secondary compounds produced by molds that are found in the soil and vegetable matter including grains, forages and feed. They can be formed in the field both before and during harvest, and can continue to be formed under suboptimal storage conditions after harvest. Mycotoxins are nothing new to the poultry, swine and ruminant markets, but less is known about the adverse effects of mycotoxins in horses. These toxins can cause a wide range of clinical signs in horses, including respiratory, gastrointestinal, neurologic, and reproductive problems–even death.

How horses are exposed to mycoto