Feed contamination is a critical risk of feed manufacturing that all feed manufacturers should account for. Proper feed quality is crucial to minimize the health risks to horses due to physical, chemical or biological contamination. Horse feed contaminated with ionophores is especially problematic, and feed manufacturers should remain diligent with safety protocols to prevent cross-contamination.  

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, and in horses, 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 a 100-percent ionophore-free manufacturing facility.  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. 
 

If you have questions about Purina feed quality or Purina horse feed products, contact your local Purina representative or retailer, or our customer service team (800-227-8941).