It is widely accepted that any presence of ionophores in equine feeds is considered toxic. We are deeply saddened by the tragic loss of horses in Oklahoma due to ionophore (Rumensin) contamination. Our heartfelt condolences go out to the Beutler family during this difficult time. 😔

At H&S Feed & Country Store, we prioritize the safety and well-being of our equine community. As a trusted Purina Feed Dealer, we want to reassure you that all Purina horse feeds are produced in dedicated, ionophore-free manufacturing facilities. You can read below a statement from Purina Mills regarding their feed.  You can also find more information on their quality standards on this issue at this link.

“As an active member of the equine community, our hearts ache when an owner loses a horse. As horse owners ourselves, we understand the importance of consistent, quality feed.

Because our feed quality is of the upmost importance, our manufacturing facilities where Purina® horse feeds are produced are 100% ionophore-free and are operated according to strict quality standards, providing peace-of-mind that the Purina feed you select is trustworthy.”

What are Ionophores?

Ionophores are a class of antibiotics that may be added to poultry and cattle diets as growth-promoting agents and as potent coccidiostats. These compounds function to alter the membrane potential of certain tissues. In horses, it can result in a multitude of aberrant clinical symptoms. Often, the first clinical symptom observed in horses afflicted with ionophore toxicities is sudden death. However, other clinical signs may develop, including unexplained colic, ataxia, diarrhea and excessive urination. Ionophores affect various body tissues, including cardiac muscle, skeletal muscle and the nervous system; therefore, symptoms are typically non-specific.

Bloodwork on horses with suspected ionophore toxicity may show elevated muscle enzymes. Horses may have individual tolerances to ionophore toxicities. Still, it is widely accepted that any presence of ionophores in equine feeds is considered toxic and levels as low as 1.4 mg per kg of body weight can be lethal. Treatments for ionophore toxicity are largely palliative and supportive, and survivors are known to have long-term health effects.

What Should I Do if I Suspect Ionophore Exposure with my Horse?

If ionophore contamination is suspected, the horse owner should work with their veterinarian to gather information related to their horse and the feed in question. Then, connect with the feed manufacturer.

What Does Good Feed Quality Look Like?

The Purina® FeedGuard® Nutrition System is an example of an effective feed safety and quality-assurance system, created to ensure quality consistency and nutritive effectiveness. To further ensure peace-of-mind, all Purina equine feeds are manufactured within 100-percent ionophore-free manufacturing lines. Additional measures taken by Purina to ensure quality include thorough inspection of all feed ingredients to ensure the absence of undesirable elements and stringent ingredient testing to confirm nutrient levels and quality.