Q: My horse often ties up after his morning training sessions. What can I do in terms of nutrition to help reduce this and manage him more effectively?

A: There are a variety of diseases/disorders that fall under the generic term “tying-up.” It is important to work with your veterinarian first to determine the cause and possible medical treatment options. Signs of a tying-up episode can range from mild to severe and can include muscle twitching, reluctance to move, stiff gaits, excessive sweating, increased heart rate, respiratory rate, and temperature, muscle tension across the back and hindquarters, and dark colored urine.

Fortunately, dietary management of horses that experience tying-up is essentially the same, regardless of the cause. It is important to limit nonstructural carbohydrates (NSC) to preferably less than 20% of the total diet, and even closer to 10% is desirable for some tying-up disorders. Commercial feed companies should be able to tell you the NSC content of their feeds, and having your hay analyzed can help you assess its NSC content.

Soaking hay can help reduce the NSC content, but you must be sure to remove the hay from the water before feeding, and don’t give your horse access to the soaking water because the carbohydrates will have leached into it. If your horse is out on lush pasture, using a grazing muzzle can help reduce his NSC intake, as well.

If your horse has a high caloric demand due to the demands of his workload or to maintain his body weight, consider a higher-fat feed and more complex carbohydrates for an energy source, such as top-dressing oils on the feed, or using another high-fat source such as rice bran. Adding unmolassed beet pulp to his diet can also help meet calorie needs without introducing more NSCs.

Be sure that your horse is receiving proper levels of electrolytes and minerals in his diet because horses lose minerals through their sweat (that is what is in that white “crust” you see on your horse’s coat when it’s hot and/or he’s worked very hard). It is recommended to top-dress feed with about 2 tablespoons of loose salt per day, especially in hotter months, as well as provide free choice salt. Besides sodium and chloride, you should also examine horses’ potassium, magnesium, and calcium levels because all these minerals are involved in proper muscle function. 

Increasing antioxidant levels in the diet will help combat free radicals, which can contribute to muscle damage. The National Research Council’s daily recommendations for the average 1,000-pound horse are 500-1,000 International Units (IUs) of vitamin E and 1 mg of selenium. These recommendations go up to 4,000-5,000 IUs of vitamin E and 3 mg of selenium for horses prone to tying-up.

It is also important to make sure your horse has access to good-quality water. Horses need to be properly hydrated for their muscles to function properly—that includes maintaining core temperature and helping move nutrients and waste products across cell walls.

Finally, you should try to keep your horse in a low-stress environment. This is not always easy to accomplish for a performance horse, but providing him turnout, feeding him first at mealtimes so he’s not waiting to be fed, and keeping to a consistent routine can assist.

These recommendations can help you manage your horse that’s prone to tying-up, but consult your veterinarian and an equine nutritionist to make sure you are doing all you can to minimize episodes and ensure your mount’s diet is balanced.