Understanding the Risks of Ionophores for Horses: Insights from Dr. Teresa Douthit

The content in this blog is derived from my interview with Dr. Teresa Douthit- Equine Nutrition Specialist at Kansas State University

I recently had the opportunity to speak with Dr. Teresa Douthit, an equine nutrition specialist at Kansas State University, about the dangers/risks of ionophores for horses and how to best avoid them.

What Are Ionophores?

Ionophores are commonly added to beef cattle rations to prevent toxic coccidiosis and promote growth. They are also used in poultry rations and can be beneficial for various species. However, horses are incredibly sensitive to even low levels of ionophores, making them highly toxic for equines.

The Impact on Horses

A small dose of ionophores may not be fatal, but it can cause lifelong damage. Dr. Douthit explains, “Horses exposed to ionophores can suffer from cardiac damage, making them intolerant to exercise. This means a horse that was once healthy and active may no longer be rideable or usable due to exposure.”

Symptoms and Consequences

The symptoms of ionophore toxicity in horses can vary. Dr. Douthit notes that in some cases, the first sign might be a dead horse. Other symptoms include colic, weakness, and an unsteady gait. Unfortunately, there is no specific treatment for ionophore toxicity. Supportive care is the only option, and even then, long-lasting consequences are common.

Why Are Horses So Susceptible?

Ionophores change the flow of molecules across the cellular membrane, but the exact mechanism of why horses are so susceptible is not well understood. Dr. Douthit mentions, “Cardiac tissue seems to be particularly affected, but more research is needed to fully understand the process.”

How to Protect Your Horses

To protect horses from ionophore toxicity, it is most safe to use feed from companies that strictly produce horse feed. These companies ensure their feed mills are 100% ionophore-free, significantly reducing the risk of contamination.

There are other companies that produce horse feed alongside other types of feed that may use ionophores. These companies have different designations for their facilities:

• Ionophore-Free Facilities: These facilities do not have ionophores on-site, ensuring that anything produced there is safe for horses.

• Ionophore-Safe Facilities: These facilities produce products containing ionophores but have quality control measures in place to mitigate the risk of contamination. They might use different equipment for horse feed or have a thorough flushing process to remove ionophores from the system before producing horse feed.

Dr. Douthit explains, “Ionophore-safe facilities might produce cattle feed with ionophores on one day and then switch to swine feed without ionophores for a few days, flushing the system in the process. By the time they start producing horse feed, any ionophores should have been flushed out.”

For the safest option, choose feeds from ionophore-free facilities. If using ionophore-safe feeds, horse owners can contact the company to understand their safety measures.

By being aware of the risks and taking preventive measures, horse owners can help ensure the safety and well-being of their animals.

Listen to the full interview here: https://youtu.be/JYQdreOvwbc