Quality of Life for the Overweight, Insulin-Resistant Horse

By Juliet M. Getty, Ph.D.

Your veterinarian just visited and told you in no uncertain terms that your overweight, insulin-resistant horse is going to develop laminitis if you don’t put him in a dry lot with a very small amount of hay. You don’t really want to restrict his hay, but you feel wracked with guilt. What if your vet is right?  How would you ever forgive yourself if your horse became ill? 

The truth is your horse is already ill. And his history will tell you just how ill he has become. If he has always been on free choice forage (hay and/or pasture) then you have a much easier job ahead of you. But if his history is one where he has not had a steady supply of forage 24/7, often for years on end, the impact on his metabolism and his brain is very tough to reverse.

If you think the solution is to continue down the destructive path of forage restriction, you will only make things worse. He may lose weight, but it will be mostly muscle loss. His insulin resistance, however, will remain and continue to promote the inflammation that is causing oxidative stress throughout his entire body including the hypothalamus portion of the brain, leading to leptin resistance, and even Cushing’s disease.

The only way to fix your horse is to help him return to his natural state. Feeding your horse in a manner that is contrary to his innate physiological needs is making his body scream for help. His hormones are raging. His brain is telling him to hold on to body fat to protect himself from the perceived threats to his survival. 

Let’s talk about quality of life… 

I believe that quality of life is what matters most. Anyone who loves a horse understands this. But how do we achieve it in a domesticated setting that is nothing like a horse would experience in the wild?  We certainly try, oh how we try – always seeking advice from others, investigating  the next fancy supplement,  spending time analyzing the diet with detailed spreadsheets, consulting with veterinarians, chiropractors, massage therapists, animal communicators, and yes, even equine nutritionists, all in the never ending quest to help your horse be better. 

But I have a secret for you.

It is simple to understand, makes perfect sense, and yet, very few horse owners know about it, or they choose to ignore it. You may already use this secret for your own health to create balance in your life by eating well, establishing priorities, and tapping into your inner self. But what about the horse’s “inner self,” where his body and mind are in sync and health comes naturally?  If the horse could tap into it, he would be better, too. Right?

And therein lies the answer -- honoring and respecting the way a horse is designed. Read that again and let it sink in. It means quality living. It means a life without daily suffering and fear. And it means a life where your horse can make choices.

If you want this for your horse, you need to become savvy in what your horse requires to be a whole being. Once empowered with this true understanding, you can weigh his needs against what you hear from well-intentioned friends and equine professionals.

Your first step is to gain some real understanding of what causes obesity and why forage restriction is a major factor in keeping your horse overweight. To help you with this, please start by reading my articles and listen to relevant recordings on the subjects of “Overweight Horses” and “Free Choice Forage Feeding Concepts” in the Resource Library[1]on my website.

“Free-choice” simply means that forage is always available. It doesn’t imply that the horse will eat 24 hours a day. Instead, it means that the horse gets to choose when to eat. When forage is not around, the horse cannot relax and will eat everything in sight and eat it quickly. It’s as though winter is coming. A wild horse will experience this during the winter when forage is scarce. His insulin level rises as a natural response so that his body can hold on to fat during the food shortage. But we duplicate this scenario in a domesticated situation when we restrict hay. The horse goes into “winter mode” and holds on to body fat!

How do you start to make changes?

Begin by testing your hay. This is a must. Most of your horse’s diet comes from hay, so feeding it without knowing what’s in it can be a dangerous mistake. You need to know if it is low enough in sugar and starch, as well as its caloric content so you can allow him to “graze” on it.

When you get your hay analysis report[2], look at the “dry matter” column and add up two numbers: ESC + Starch. ESC refers to simple sugars. Along with starch, they impact insulin levels. The familiar “NSC” includes fructans which do not raise insulin levels, so it is not as accurate to look at WSC (which is ESC plus fructans). The ESC + Starch should ideally be no more than 10%.

Also look at the digestible energy (DE). This is a measure of how caloric the hay is. A value no higher than 0.94 Mcals/lb (2.06 Mcals/kg) is favorable for the overweight horse.

If these values are too high, you may need to soak your hay. Soaking can be labor intensive, but if you have a bucket with a drain on the bottom, it is not as hard as you think. However, it is likely not feasible during freezing temperatures. In that case, keep searching for another hay that you could possibly use to “dilute” your current hay.

If your barn brings in new hay every week or so, you may not be able to have it tested (unless it comes from the same grower). In this case, consider bringing in your own supply of hay and, if need be, paying for storage space. This is your horse we’re talking about, who is completely dependent on you.

Once you’ve determined your hay is appropriate, offer it free choice

There needs to be enough to never run out. There should be some left over in the morning, so you know your horse didn’t run out during the night. At first, your horse will overeat. In his mind, spring is here, after a long, brutal winter!

Don’t make the mistake of just increasing the amount. If you just give your horse more hay, but he runs out, even for a few minutes, he will always assume that forage is scarce and will never reach the point when he can walk away from it. Yes, walk away from it – that is the magic moment! It can take a week to occur, or it can take months. Every horse is different.

You can also test your pasture. If you are fortunate enough to have pasture, you could consider testing it. Every two weeks will give you an idea of how it is behaving. Keep in mind, however, that during the fall and spring seasons when there are warm, sunny days and cold nights (typically below 40 degrees F), the grasses will hold on to the sugar and starch they accumulated throughout the daytime, making the grasses more dangerous for your insulin resistant horse. You can determine just how your pasture is behaving by testing the sugar and starch level in various conditions.[3]

There are many benefits to pasture grazing

If your horse is currently in a dry lot with hay and not doing well, and you have access to pasture (especially one which has a variety of grasses and edible weeds, and is not fertilized), you may want to consider gradually switching him from a dry lot to pasture. Realize that the more dangerous times are typically in the late afternoon after a sunny day, or during the early spring and fall seasons.[4] Other risky grasses are those that are drought stressed, over-grazed, experiencing excessive rainfall.

While it is enormously important to avoid pasture during uncertain times, if you’ve determined that your pasture is low enough in sugar and starch to allow grazing, consider the pluses of giving your horse this opportunity:

  • Movement: Researchers at Louisiana State[5] looked at horses who were fed hay in a dry lot versus those that were able to graze on pasture and found that the horses in the dry lot were more insulin resistant than the horses in the pasture.
  • Healthy microbiome: When grazing, the horse picks up a variety of beneficial organisms to help him maintain a healthy microflora in the hindgut.
  • Higher nutrient content: Fresh pasture grasses offer a variety of antioxidants, vitamins, and essential fatty acids that are no longer found in hay in sufficient quantity to maintain health.
  • Socialization: Horses who are accustomed to grazing effortlessly, interacting with other horses, and moving about, will exhibit stress-related responses when suddenly confined to a space that doesn’t allow them to enjoy behaving naturally.
  • Lower forage consumption: Interestingly, horses who graze on pasture 24/7 will eat far less grass than those who are only allowed to graze on pasture for a few hours each day, with hay provided the rest of the time. Researchers have confirmed this in controlled studies.[6]

If you’ve tried this approach without success, take a closer look

Fixing the damaged horse takes effort, money, and patience. Sometimes it can take as long as a year for the horse to gain back his instinct to maintain a normal body weight.[7]  

Creating a stress-free environment is paramount to creating a balanced hormonal response that supports weight loss. Start with the foundational truth that horses are meant to graze at will, while providing opportunities for movement, exploration, and companionship. This means that stalling should be limited as much as possible, or even eliminated.

The basis of the diet must be forage – suitably low in sugar/starch/calories so that it can be fed in a manner that allows for 24/7 grazing. Have enough land for a Paddock Paradise?[8] It is a wonderful way to provide domesticated horses with an environment that simulates a natural habitat. If not, consider using slow feeders in a variety of locations to encourage movement and slow down hay consumption.[9]

Aggressive dietary strategies that offer specific supplements will help reduce inflammation, normalize insulin and leptin, and offer enough nutrients to feed the entire body. The following key supplements have been used with great success:[10]

  • Comprehensive vitamin/mineral supplement. If the diet is hay-based, this is necessary to fill in nutritional gaps that exist with hay.
  • Docosahexaenoic acid (DHA).[11] DHA is an omega 3 fatty acid that is powerful at reducing inflammation caused by excess fat.
  • Butyric acid.[12] Butyric acid is one of the three volatile fatty acids that are naturally produced by the microbes in the hindgut during hay fermentation. At higher levels, it is helpful for metabolic syndrome (as well as digestive disturbances).
  • Gymnema sylvestre.[13] This herb has been used for years with people suffering from type 2 diabetes to help lower insulin.
  • CBD.[14] Studies with horses are just beginning, but CBD has been shown to help with weight loss in people. Many of my clients have seen declines in blood insulin and leptin levels in their horses.[15]
  • Hemp seeds.[16] Not only does hemp provide an excellent quality protein, but its fatty acid content helps alleviate the inflammation caused by excess insulin.
  • Lipoic acid.[17] This is typically added to equine supplements designed to alleviate metabolic syndrome symptoms.


  • Added iron. Forage is already high enough and excess iron exacerbates insulin resistance.
  • Soy. This includes soybean meal, soybean hulls, soybean oil, etc. because most soy grown in the US is genetically modified to withstand being sprayed with glyphosate from RoundUp. This has been shown to negatively impact the microbiome[18], increase toxicity to cells[19], and reduce absorption of key minerals.[20]
  • Added sugar and starch. This includes cereal grains, grain by-products in large quantities, rice bran, and molasses.
  • High sugar treats. Most commercial treats contain oats and molasses. Check the label. Carrots and apples may not be appropriate except in extremely limited quantity.

Establish a baseline

As your horse progresses, you’ll be better able to assess his improvement by starting with certain measurements:

  • Measure the neck, halfway between the poll and the base of the wither. Divide this number in inches by the horse’s height at the top of the wither. A value of greater than 0.63 likely indicates insulin resistance.[21]
  • Blood tests: Insulin, Glucose, and Leptin. Test while your horse has access to hay, but at least three hours after offering supplements.
  • Test for Cushing’s disease if you suspect that this could be an issue.

Bottom line

Your horse brings you so much joy, especially when he is healthy. Bring back the sparkle in his eye by respecting his need to be a horse. If your insulin resistant horse has endured years of being fed forage only intermittently throughout the day, while waiting for hours for more hay, he is damaged. Bring him back to a healthy state. It is so well worth the effort.


[1]Resource Library, Getty Equine Nutrition LLC. 

[2]Equi-Analytical Labs is an excellent lab that provides test results that related to horses. Their “Equi-Tech Test #601” is recommended. https://equi-analytical.com

[3]Getty, J.M., Pasture for the insulin resistant horse.

[4]Take the time to educate yourself on how your grass behaves. Katy Watts of https://safergrass.org offers many valuable resources.

[5]Lestelle, J.D., Earl, L.R., Thompson, Jr., D.L., Hebert, R.C., and Mitcham, P.B. 2011. Abstract: Insulin-glucose dose response curves in insulin sensitive and insensitive mares and effect of overnight and long-term feeding regimen. Journal of Equine Veterinary Science, 31, 285-286. Louisiana State University Agricultural Center. 

[6]Glunk, E.C., Pratt-Phillips, S.E., and Siciliano, P.D., 2013. Effect of restricted pasture access on pasture dry matter intake rate, dietary energy intake, and fecal pH in horses. Journal of Equine Veterinary Science, 33(6), 421-426.

[7]Getty, J.M., Respect the power of the horse’s instincts. 

[8]Learn about this management system developed by Jaime Jackson: https://paddockparadise.net/

[9]Getty, J.M. The correct way to use slow feeders. 

[10]For a specific, customized plan for your horse, it is best to consider a phone consultation. These supplements can be found on line, as well as at Dr. Getty’s Free Shipping Store 

[11]Research review by Juliet M. Getty: Impact of DHA supplementation on inflammation reduction in metabolic horses. 

[12]McNabney, S.M., and Henagan, T.M., 2017. Short chain fatty acids in the colon and peripheral tissues: A focus on butyrate, colon cancer, obesity and insulin resistance. Nutrients

[13]de Laat, M. A., Kheder, M. H., Pollitt, C. C., and Sillence, M. N., 2018. Sweet taste receptor inhibitors: Potential treatment for equine insulin dysregulation. PloS one13(6). https://doi.org/10.1371/journal.pone.0200070

[14]Ferdinand H. Quinones, M.D., 2019. Book: CBD OIL & METABOLIC SYNDROME: Everything You Need to Know About CBD OIL AND METABOLIC SYNDROME. https://www.amazon.com/CBD-OIL-METABOLIC-SYNDROME-Everything/dp/1097644375. Also:  Burstein, S., 2015. Cannabidiol (CBD) and its analogs: a review of their effects on inflammation. Bioorganic and Medicinal Chemistry. In Press. https://gettycbdhealth.com for tested CBD choices for your horse.

[16]Opyd, P.M., Jurgoński, A., Fotschki, B., and Juśkiewicz, J., 2020. Dietary hemp seeds more effectively attenuate disorders in genetically obese rats than their lipid fraction. The Journal of Nutrition, 150(6), 1425-1433. https://academic.oup.com/jn/article-abstract/150/6/1425/5818727. Also, Getty, J.M., Choose hemp instead of soy! 

[17]Crandell, K., 2011. Effect of lipoic acid supplementation in horses. Kentucky Equine Research Equinews: https://ker.com/equinews/effect-lipoic-acid-supplementation-horses/#:~:text=Their%20regulation%20is%20often%20disturbed,in%20humans%20and%20certain%20animals.

[18]Robinson, C., and Perro, M., 2020. Glyphosate and Roundup Disrupt the Gut Microbiome by Inhibiting the Shikimate Pathway. GMO Science. https://www.gmoscience.org/glyphosate-and-roundup-disrupt-the-gut-microbiome-by-inhibiting-the-shikimate-pathway/

[19]Youwu, H., Yang, Z., Hongfei, N., et. al., 2019. Evaluation of the cytotoxic effects of glyphosate herbicides in human liver, lung, and nerve. Journal of Environmental Science and Health, 54(9):737-744. https://pubmed.ncbi.nlm.nih.gov/31232652/

[20]Mertens, M., Hoss, Se., Neumann, G., et. al., 2018. Glyphosate, a chelating agent – relevant for ecological risk assessment? Environmental Science and Pollution Research International, 25(6). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5823954/#:~:text=If%20glyphosate%2C%20in%20fact%2C%20binds,organisms%20feeding%20on%20such%20plants

[21]Neck circumference measurement: Getty, J.M., 2013. Easy Keeper: Making it Easy to Keep Him Healthy. Spotlight on Equine Nutrition Series. Page 8. 


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For permission to reprint this article, in part or in its entirety, please contact Dr. Juliet Getty directly at Gettyequinenutrition@gmail.com.