Your horse is footsore. Your veterinarian has drawn blood and determined that your horse had high insulin levels. How can you lower insulin?
Horses that experience high insulin levels frequently have footsoreness, or laminitis. Horses differ from humans in that humans will frequently get high blood glucose. Horses more often have high insulin levels, but normal glucose. Strategies that may help people reduce their blood sugar may not be helpful to the horse.
◆︎ Exercise:
By far the most natural method of lowering insulin levels is through exercise. Regular exercise helps keep a horse conditioned, maintain a good body weight, and helps to keep the insulin levels in check.
The problem is that high insulin numbers frequently result in a horse being footsore, or having laminitis. And a horse that is footsore is compromised by the amount of exercise they can comfortably do. If you have a horse that is prone to high insulin numbers, exercise may reduce the risk of laminitis. Once your horse has laminitis and isn’t able to exercise extensively, diet, supplements, or drugs then become the next tools to help lower insulin.
◆︎ Diet:
The culprit in the diet is anything that will raise insulin levels. We usually think of sugars and starches raising insulin levels. So dietary strategies involve ways to lower sugar and starch in the feed.
Avoid pasture. Grazing is unsafe for horses with high insulin. Sugars fluctuate in grasses. During the day, more sugar is created through photosynthesis. Plants have higher sugar levels in the evening than in the morning. Plants also have higher sugar levels in the spring to fuel spring growth. Higher levels are found when the plants are stressed by drought or widely fluctuating temperatures (think cold nights and warm days). Springtime is a common time for horses to become laminitic due to grazing on the spring growth with higher sugar levels.
Avoid bagged feed unless it has a guarantee of under 10% sugar + starch. Although tasty, bagged feed frequently has high levels of sugars and starches. Even bagged feed that is labelled as “low starch” may have levels that are too high for horses that already have high insulin levels. Feeds that contain wheat, oats, corn, or other grains have higher levels of sugar and starch.
Test your hay. The only way to know if the hay is low in sugar and starch is to test it. If the grass had high levels of sugars prior to baling, the hay may also have high levels of sugar and starch. If you’re unable to test your hay, consider soaking the hay. Soaking can remove as much as 40% of the sugars, although that number is variable.
Consider feeding beet pulp. Beet pulp is one of the preferred feeds because it is fermented to volatile fatty acids in the hindgut. Since there is little absorption of sugars in the foregut, insulin levels tend not to spike. It is recommended that a 1000 lb horse eat no more than 3-4 lbs of beet pulp per day. It’s important to remember that beet pulp has 1 ½ to 2 times the number of calories than hay, so it is not a low-calorie food.
◆︎ Supplements:
Some horses respond favorably to nutritional supplements. Anecdotal reports show that some horses respond to:
➡Magnesium: MagOx or Magnesium glycinate. 3 grams of elemental magnesium per day for a 1000 lb horse. This equates to 5 grams of MagOx or 13.5 grams of magnesium glycinate.
➡Acetyl L-Carnitine (ALCAR): Some horses respond at 10 grams per day for a 1000 lb horse
➡Spirulina: Some horses respond when fed 100 grams of spirulina per day. This could be as a powder in their feed, or as tablets.
➡Resveratrol: Anecdotally, some people have found satisfactory results with 350-1400 mg per day.
➡Quercetin: Some horses do well on 2-5 grams once or twice per day.
More research is necessary to determine the effectiveness of supplements.
◆︎ Drugs:
It’s important to work with your veterinarian for advice on the administration of insulin sensitizing drugs.
Metformin: Metformin recommended dose is 35 mg/kg body weight twice a day. This is 15 pills (1000 mg pills) fed AM and PM for a 1100 lb horse.
-Flozin drugs: Some veterinarians will prescribe ertugliflozin at .05 mg/kg daily or canagliflozin at 0.3-0.6 mg/kg daily. However, careful monitoring of triglycerides and liver enzymes may be necessary.
Currently, there is no magic bullet to help reduce insulin numbers. Many people need to use a combination of strategies to manage their horse’s insulin levels.
We do the best that we can for our horses. Understanding options available to us for controlling insulin levels is a part of that.
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Disclaimer: Statements regarding dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease or health condition.
©Joan Kulifay 2025