Diets of horses with a history of laminitis (founder) should be kept to less than 12% non-structural carbohydrates.
Question: I have a mare that came down with laminitis this spring (I did take acclimate her to pasture). The barn where I board has very "rich" hay; 60% legumes and 40% grass. What are some recommendations for feeding a horse post laminitis?
Response: Now that your horse has foundered, you should try and keep her overall diet to less than 12% non-structural carbohydrates (NSC). If she is in good body condition, do not feed her grain or treats. Maximize her forage and include a ration balancer (vitamin, mineral, amino acids) to fill in any essential nutrients that dried hay (even good quality) lacks. Unlike grain, ration balancers are fed in small quantities.
Since hay will be your primary source of nutrition, it is essential to get the hay tested. Once you receive the results, look for the NSC value or add together the water soluble carbohydrate and starch vales to estimate NSC. Hopefully that number is close to or below 12%. If it is, great! If not, you might want to consider a quick soak (15-30 minutes) in water to remove some of the carbohydrates. Some horses may recover and can return to a "normal" diet. Before making any changes, work with both your veterinarian and an equine nutritionist.
The alfalfa will actually be helpful in your situation since alfalfa tends to have less NSC compared to grass. The reason most horse owners with laminitic horses shy away from alfalfa is because of the higher caloric content compared to grass. Most laminitic horses also tend to have a weight problem, and feeding energy dense alfalfa hay will only make that problem worse.
In the future, look for a mature (i.e. seed head and flowers) mixed alfalfa-grass hay, or hay that has taken a long time to dry (slightly yellow color), or had a light rain prior to baling. These hays tend to be naturally lower in carbohydrates.
By: Krishona Martinson, PhD, University of Minnesota