Here is a new word for many of you, but we have known about them for a while. A lectin is a protein made by plants. OK, so far?

The things I will be writing about here are mind-blowing – and very new. I am excited about this information for a lot of reasons. The most important reason for horse owners is that lectins are generally not good. For example, about 5 and 6 years ago, the Nobel prize was awarded for research on lectins as a cause for making insulin ineffective. Can anyone say insulin resistance?

As a scientist (a veterinarian is a scientist), I was becoming frustrated by our profession’s quickness to diagnose, test, and treat a disease without fully understanding why the disease occurs. It became the “But why Mommy?” syndrome as she would finally reply, “Because I said so.” So let me start by telling you what lectins do.

We all know about the immune system within ourselves that defend against attacks by bacteria, viruses and other bugs trying to take over our bodies, but did you know that plants also have a system to prevent attacks? Further, did you know that many plants do not want to be eaten? This especially applies to their “babies,” or seeds. During the 100,000 years that modern humans have been alive, and I assume horses, we have learned to live with certain plants willing to become our food without becoming sick or dying.

Remember, in a past blog (Doughnut Hole) I said that anything you place into your mouth and swallow is NOT inside you. I further noted that the food you eat is there to feed the bacteria living in your Gastro-Intestinal Tract (GIT), and in turn, they feed us (Symbiosis). So when something new is introduced to our GIT, such as a foreign protein of new food (a lectin), an alert is sent to our immune system. The first line of defense is the mucous covering our food and gut lining, which binds to these foreign proteins and escorts them out of the GIT without damage. But when there are 1) a lot of these lectins and 2) a lot of dead bacteria, damage to the gut lining is soon to occur. The result is a leaking gut.

Many have heard of leaking gut syndrome but let me explain. The GIT has a skin modified from the skin you see on the back of your hand. The transition occurs at your lips and anus and is called the gut mucosa. It is primarily made of ONE cell layer called the endothelium and backed by a thicker group of cells ready to replace this endothelium when it dies. The purpose of the endothelium is to prevent harmful molecules from getting in while allowing good molecules to pass easily. Pretty simple. You and your horse have been doing this for millions of years.

Then humans decided to make things better. We found that we could grow grains and store them making them available for use in winter when food was scarce. Interestingly, no bone osteoarthritis was found in archeological sites until the Egyptians and the Pharos. And guess who ate more grains than any other human on Earth? Yup – the Egyptians. The lectins of wheat are now well known, including the common gluten and the more destructive cousin Wheat Germ Agglutinin (WGA). Then explorers such as Columbus brought back new foods such as tomatoes, squash, cucumbers and others from the family called nightshades and these lectins are particularly destructive. Only 500 years ago, the introduction of nightshade lectins and their associated destruction came to our gut naive bacteria.

The damage caused by the invading foreign proteins creates a space between the endothelium cells where more lectins can walk right into our body – hence the name leaking gut. The damage leads to more foreign invaders, more inflammatory immune response, more disease and ultimately, fewer animals eating the plant and, therefore, a better chance for the plant to survive.

The popular and pervasive feeding of grains to all horses is about 50 years old in horses. In 1973 as a stall mucker, I would go to the railroad yard with the other workers and unload a box car full of racehorse oats. A tough day and certainly harder than your ability to pick up the phone and order a few bags of that fancy feed with the pretty pictures, catchy name and a back panel filled with unpronounceable words – and STACKED IN YOUR FEED ROOM by the strong delivery person!

Guess what? Most of the diseases so popular today in horses were uncommon back then. Reading the vet texts written in the late 1800’s you will find little of what we see today. The common and persuasive change seen throughout this country in the care of the horse is the introduction of abundant and readily available grain with their associated foreign lectin proteins. Please understand that this is only a hypothesis based on human research, but for me, it explains why so many horses removed from grain show such positive results.

What about whole grains like the racehorse oats we fed 45 years ago? I’m just guessing, but wheat middling, I assume, is loaded with WGA, which may be at the root of insulin resistance. While a no-grain approach is the safest for the horse, if you can’t stop feeding grain, try the no-grain approach for at least six weeks to fully heal the gut endothelium. Then, if you want something to add, go with the whole grains, especially in horses over 30 years with weight loss or severe winter weather approaching. In my experience, the results from a no-grain diet will stop you from ever feeding grain. (See the article in “The Horse” titled Racing Standardbreds on an all forage diet)

Enough? Don’t worry because, in future blogs, I will explain why WGA is a lectin that mimics insulin and prevents insulin from doing its job (insulin resistance) and why horses on a no-grain diet lose fat, exposing the existing chronic muscle starvation (a common reason owners put the horse back on grain), why hard keepers start to gain weight once off of grain and more. This information is new and exciting for all horse owners everywhere. If you want to read a great book on this subject, pick up a copy of “The Plant Paradox” by Steven R Gundry, MD. It is fascinating.

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  1. Doc T, article on lectins interesting BUT…
    I want you to look deeper into this serious
    Problem, that is causing immune diseases
    In millions upon millions of people and
    From your article, replies from people
    Their horses…
    (1) the problems are from Agriculture sprays to kill weeds, such as glysophate
    (Roundup, Dicamba, etc.) and all the pesticides, fungicides, etc that are currently being sprayed on our crops, foods we eat, foods horses eats, grains, etc.
    These “sprays” are getting more and more in the foods we eat, and have become a epidemic sweeping not only the U.S. but worldwide!!!
    Horses are being fed more and more
    grain by products, soyhulls, ddg, on and on which concentrates “spray residues” even
    More more in these products…
    Even most oats have these chemical residues from greedy farmers spraying
    Oats, wheat, etc. Just before harvest
    When grains still green to kill the plant so
    They can harvest sooner to be able to plant another crop…
    This practice, spraying is basically giving
    These grains ” a bath in these poisen sprays!!!
    You can’t even go to store purchase a box of oatmeal without getting a dose of these
    Sprays to eat for breakfast! In baby food,
    All of what was healthy food to eat now
    Including fruits, you name it has these residues in them…
    Their may be something ” about lectins”
    That makes these foods worse???
    But I believe it’s just because a lot of ” lectin foods are receiving so much of
    These Sprays!!!
    See, EWG, The environmental group,
    That are helping to bring this ” serious problem” to the public!!!
    Thousand of scientists worldwide are
    Currently doing studies on the effects
    On our gut bacteria, which are essential
    For health , our immune system, even our brains! Causing so much suffering by so many! From these Sprays!!!
    My understanding is Roundup is also
    A patented antibiotic also, that we are all
    Consuming, with antibiotic resistant diseases increasing everyday…
    I hope this helps you in your quest to
    Help our horses…
    MSC, Multiple chemical Sensitivity is
    Another result of all these poisen chemicals in our environment…
    Dr. T feel free to contact me to help you fill in the blanks…
    Just understand, God did not create
    Grains, such as wheat, that’s been here
    Since creation to cause us and our horses
    Health problems…

    1. Kevin – I appreciate your passion for the message about herbicides and pesticides causing harm to the gut’s microbiome. There are data supporting this and as you say, it is difficult to avoid these chemicals in everyday products for horses.

      However in my opinion, feeding grain every day of the year is harmful to horses and because the effect of lectins, feeding any grain at any time is probably harmful. They can cause leaky gut as well as mitochondrial exhaustion leading to protein resorption. The chronic protein is evident in almost all horses I see and the removal of all grain and the addition of a high quality protein source is improving horses beyond expectations. The gut microbiome appears to be restored as well.

      In my observations, while the adverse effects of the chemicals you mention may still occur, the continuous feeding of starch (sugar) beyond the daily needs, the lack of available essential amino acids and the absence of a period where glucose is limited (hormesis) all are leading to the early demise of health in horses.

      Removing grain and limiting hay will significantly reduce the intake of applied chemicals. There is organic hay and soybean meal available. The pastures are controlled by the horse owner. Therefore the approach I suggest to feeding horses is in alignment with your concerns if the horse owner is willing to purchase organic feeds and maintain their pastures correctly.

  2. Hello again,
    I enrolled in your equine nutrition and dentistry courses. But, I have another question, if you don’t mind, what is your perspective on too much iron such as in years of being on high iron well water? With all of the health problems that I am having with my horses before coming across the lectin connection I have always thought that the iron may have played a part and some veterinarians will say definitely but more will say absolutely not. I’ve read and talked with some that say high iron will prevent other necessary minerals from being absorbed creating deficiencies which can cause numerous problems. I’m just wondering if you have any opinion on this? Thank you!

    1. In humans, iron is regulated. With normal amount of iron within the body the absorption of iron is not allowed. I can only assume this could be true for horses. In addition, iron loss only occurs with hemorrhage (blood loss). Otherwise iron is well preserved within the body. If blood loss occurs within the body it is usually absorbed in the fat permanently. My conclusion is that excess iron isn’t a problem.

      How many horses have you seen or read about with mineral toxicity or deficiency (assuming not starved)? I cannot find any but I do see chronic protein deficiency and gut inflammation everywhere. Let’s get these 2 things corrected before we worry about minerals and vitamins. I know this will ruffle feathers in the horse community, but get the house in order first with what we KNOW is a problem. After this we can look at the other things which seem so difficult to assess.

      THANK YOU for enrolling!! Learn and share please.

      1. Thank you! I am noticing an improvement since having gone strictly back to hay and pasture only. I am so grateful and look forward to learning more through your courses.

  3. I pulled everything but pasture, hay and salt from my horses three weeks ago at a time I was also backing off on workload for a couple of weeks. Do you recommend waiting six weeks before adding anything more back in, or is that just if you are considering grain?

    I want to feed protein and amino acids and am looking at a combination of:
    Barn Bag

    I’m particularly focused on an upper level dressage horse that needs support for his topline muscling and demanding workload but that has a history of ulcers and sometimes explosive behavior.

    I do think a couple of my older horses have chronic protein deficiency and am thrilled with the info you have provided in your blog that led me to see it.

    Is there anything repetitive or problematic that you see in using these three feed sorces to supplement the pasture, grass hay, and flake of alfalfa each horse is currently getting?

    I will tailor to the work load and condition needs of the individuals, with each getting Barn Bag and adding Coolstance and SBM as needed.

    Thank you for your time!

    1. Once off grain you should never need to go back to it. Grain includes all seeds as the lectins in any seed may be inflammatory to horses.

      Proteins ARE amino acids. Please read these 2 articles: https://theequinepractice.com/decomplexicating-equine-nutrition-08-the-importance-of-protein/ and https://theequinepractice.com/protein/

      SBM is all you will need but BarnBag is good. Coolstance is a great non-inflammatory source of fat for horses that need to gain condition (old horses) but is not as good a protein source as SBM and is not needed in addition to SBM especially if the pasture is good and you are feeding a flake of alfalfa every day.

      “I will tailor to the work load and condition needs of the individuals, with each getting Barn Bag and adding Coolstance and SBM as needed.” For any working horse (any sport) I would feed pasture, water, pure salt (no sugar or binders added), grass hay, 1 flake of legume hay (alfalfa, clover, peanut) and 1 pound of soy bean meal (SBM) every day. Only if the horse needs additional condition (old horse, severe winter weather) would I add Coolstance. Barn Bag would be needed only if SBM was not available or you wanted to feed less SBM for some reason.

      Remember to allow some time – up to 6 months – for the horse to adjust condition and replace loss muscle mass and other proteins (hoof, connective tissue, enzymes, neurotransmitters, hormones and more). By the way, I have permission to say this – Shelly Francis uses this protocol and as a dressage rider, both she and her horses are doing very well on this.

  4. I came across your article from searching for information on lectin. I am so glad that I did! As you mentioned I am reading “The Plant Paradox” and I’m wondering if this is the missing link to all of my horses’ issues. Currently my horses only get pasture and a grass/Alfalfa hay mix, no grain/feed, but for years I was guilty of feeding grain. This may be a dumb question but can the lectin in grass or my hay be a concern? I’m new to the lectin issue, can hay be tested for this and is it like other things that you are testing for, where the numbers tell the story or is it either it’s there or it’s not? Which I’m assuming since it’s in plants it’s there? Lectin is something that I want to learn about and understand. I am a person who needs to understand “WHY” and “How do I fix it?” not just “Use this medicine and hopefully the problem will go away.” Thank you!!!

    1. Lectins are new to human medicine and nutrition and not even mentioned in horses – until now. It is one part of the multiple reasons for so many new or the increased incidence of illnesses and unsoundnesses in horses today compared to horses raised 40 or more years ago. The other factors include genetics and the continuous feeding of carbohydrates throughout the year.

      If you are looking for the “why” then consider enrolling in the Horsemanship Nutrition Course. I dig in deep and move you through the simple and elegant ways horses process the raw materials placed in front of their mouths. And I have more blogs coming!!

      As far as lectins in grass and cut grass (hay), I do not believe there is a cause for concern as horses were developed to graze on these plants. There are no routine tests for lectins in horse feed. Just the rule of thumb that all soft seeds (grains) are plant babies and do not want to be eaten. However there is a genetic overlay to this which can be summed up in a question: How do you feed an Egyptian Arab, a Peruvian Paso and a Mongolian horse all living in Mississippi? It does become tough in that some grasses may have an adverse effect on some horses. And not just the grass but the things growing on the grass. I just floated a barn of horses where 1 horse had the clover drools (not pleasant to work in that mouth) while the others seemed unaffected. But as a generalization, I think eating what the ancestors ate should not be bad for horses. Pasture and cut pasture should be OK.

  5. I am an equine bodyworker, continuing my education in equine Osteopathy. I have a true belief in our health and our horses health, coming from what we eat and our our ability to absorb it by having a healthy gut biome. Thank you so much for your in depth but easy to read and understand blogs on nutrition. They are a gold mine! I am sharing on my Facebook Page and have had thousands of people reading and commenting and I hope taking your no grain challenge! So glad I found you.

    1. I am so grateful for you posting this. Over time we all can get this right which will make the horse’s lives a lot better. Thank you, Doc T

  6. Doc T, I see in your article above that you suggest feeding whole grains if a no grain diet is not feasible. I thought I had read in one of your previous articles that if extra calories are needed to try something like Coolstance, which I have done. So I’m a bit confused.

    Here is my situation. My horse is currently on a diet of Alfalfa pellets (a bit less than 2 qt. daily), about 3/4 of a cup of Coolstance, High Point Grass vitamins and minerals, and High Point joint supplement (which has no sugars or grains added). He is out 24/7 and there is still grass available , but I am also feeding a good bit of hay at this point. My horses always have forage available – either hay or grass or both. We have recently greatly increased our riding time and intensity and my guy doesn’t need to lose any weight. With the increased work load I feel like he needs extra calories over the winter months, which are also our most active riding months. What do you suggest? Should I be using oats instead of Coolstance? Increase Coolstance? Increase Alfalfa pellets?

    BTW – my horse is still sweating like a champ.

    1. The intention of that paragraph was to address horse owners that are adamant that horses need grain. I am conceding to them that if they insist on feeding grain, onluy do so after a 6 week healing period of not feeding any grain followed by whole oats. It may be the WGA of wheat middlings that is causing the most inflammation.

      However if more calories are needed for whatever reason, they should be added by a non-inflammatory feed. Coolstance appears to be noninflammatory in horses and is a viable avenue. Usually a pound a day for a norml size horse is adequate especially for horses that are 20 to 25 years old and up.

      In your case, I see no added protein. To keep condition on a horse that is working a broad variety of proteins needs to be added after the gut inflammation has resolved. Please read this article on chronic protein deficiency in horses. Horses in my practice off of grain and on hay and ProAdd Ultimate are so robust that I can’t recognize them after a year on this feeding program.

      The bottom line is to NOT add any grain – even straight oats. Add a protein source before increasing hay or Coolstance.

  7. Hi Doc – I had switched over to a non-gmo feed a couple of years ago, fed wet (coconut meat not dried in high heat) along with a mineral that I have been using for 10+ years now (Equi-Pride) which has flax included. But, I have 1 older horse (20’s) who had a major injury when he was younger and had a broken pelvis from falling into a gopher turtle hole. He healed and just living out his life on the ranch. He is skinnier, but the less weight he has on him I would assume the better. But, I thought it was too much so he also get Horse Manna & Beet Pulp & Alfalfa Pellets soaked overnight which defeats the non-gmo feeding at this point. He cannot eat hay anymore. He has not gained any weight – even when I was feeding him 3 meals a day. Can you elaborate as to what you might suggest?

    1. I cannot offer direct advice because I have not seen your horse. You would need to get a physical from your vet to determine if there is some other problem other than nutrition.

      Some things to consider are any loss of bowel integrity (leaking gut). Look for signs of soft manure or squirts for example. I am careful with supplements including SUGAR beet pulp (I use the real name). Horse Manna is a good source of protein but is often not fed in an adequate quantity. Aim for a pound a day or even 1 1/2 pounds per day to start with. A better product is Nutrena’s ProAdd Ultimate or Nutrena’s Top Line Extreme (prognutrition.com for both) or Platinum Performance Equi-Whey (https://www.platinumperformance.com/equine-equi-whey ). Of course, all the pasture and hay (soaked cubes, soaked hay pellets, or any forage he can chew and swallow.)

      Please let us all know how he does.

      1. so is beet pulp or beet pulp based feeds bad? am dealing with a cushing horse a horse with the equine dental diseae (cement mouth) both very senior.and 2 thoroughbreds not seniors. I feed and a hay (orchard grass and alfalfa) and pasture turnout here in south east usa. my horses eat grain neutrena products senior ,proforce fiber, and por force fuel. am trying manage it all appropriately yet simplify if that makes sense. am removing lecithin from my diet also. oh my its overwhelming!!!

  8. What is suggested as a substitute for supplements (electrolytes, joint supplements Ect)?as I give so little grain goi g grain free will be simple but what about the rest?

    1. This is a good question which I will answer in a blog in the near future. But in a nutshell, removal of lectins in a horse’s diet will alleviate the need for adding supplements, especially joint supplements. This is because you will be eliminating the cause rather than supplementing for the condition.

  9. So, regarding Nutrena’s response – are they implying that the addition of pre and probiotics mitigates the possible damage from things like wheat middlings? Am I reading that wrong?

    1. From my perspective, why is there something added that possibly causes gut damage to which something else needs to be added to mitigate it? Is there another advantage to feeding wheat middlings that outweighs the possible damage PLUS the added cost and unsubstantiated effects of pre-biotics? Goodness!

      I am trying to learn here and I need some good information looked at by scientists without an agenda. What I have seen are positive results associated with the removal of grain including wheat middlings (behavior, sweating, weight gain or loss). I am suggesting that it is the lectins in the byproduct of the wheat as has been found in humans. Pre-biotics will mitigate the damage caused by lectins in humans, but why feed horses susceptible to the effects of leptins in the first place unless they offer something more significant to the health of the horse?

  10. Thank you for this article. After reading it, I contacted Nutrena, which produces the Safechoice Maintenance that I feed my senior horses. I asked whether the product contains wheat middlings — it does, in quantities greater than 50% of total ingredients. And I asked about their research into lectins. Their answer sent me digging deeper, but I am not enough of a chemist to understand most of what I am reading.

    This is the reply I received from Nutrena:

    “Interesting question Dale.  We monitor research in multiple species and do our own research on the impact of a variety of nutrients on gut health and tissue integrity.  We understand that some specific oligosaccharides may reduce the adverse effects of pathogenic bacteria by inhibiting adherence to enterocytes.  Mannose specific lectins may be involved.  (Nutrient Requirements of Horses, Sixth Edition, page 193.) 

    “We have been using a combination of prebiotics and probiotics for quite a number of years, along with specific trace mineral combinations and sources, to both provide benefits of competitive exclusion and maintaining tight junctions in the lining of the gut to help maintain gut health and support immune system. The combination we have used has been very effective in our Senior Horse feeds.”

    So I looked up mannose specific lectins and got even more confused.

    Can you kindly elaborate (in layperson’s English!)?

    Many thanks,


    PS. I load and unload my own feed and hay. Just saying.

    1. Thanks Dale. the people at grain companies are invested in understanding nutrition and are very good at it. However, there are some people like me who have listened and have become frustrated in applying what we know to what we see. This is where I am now and because of this I have opened up some ideas that are helping me explain things a little better.

      Oligosaccharides is part of the defense against lectins by binding them and eliminating them. But this is a very small part of the issue. Rather than looking at the specifics, lets look at the results of non-sweating horses that now sweat 3 days after removing all grain. How about the skinny horse that now gains weight once grain is removed? What about ill-behaving horses (bucking, unwilling to be groomed or clipped, resits tightening of the girth and more) that now are relaxed and cooperative with grain removal? In my mind, no one has adequately addressed why grains including wheat middlings can affect so many things. I am also interested in autoimmune diseases which may include insulin resistance and pituitary dysfunction.

      What is needed is more data, but no one would have a vested interest in doing this. If diseases and behavior are eliminated or improved by removing grain from the diet then grain businesses (dealers, truckers, farmers, equipment manufacturers, etc) and veterinarians would have their jobs eliminated or restricted. Even farriers would have difficulty as decreased gut inflammation and increased protein utilization improved hoof quality. Who then will prove this association? The answer is horse owners themselves. In a 2 week trial of eliminating grain, owners would be able to observe for themselves the results without spending a dime AND being able to return to feeding grain if it doesn’t work.

      Unfortunately most people are not scientist. And if they were wishing to further understand it, they will ask questions from experts and receive answers like the one you received here. Very frustrating.

      But there is one good thing here. Because you load and unload your own feed and hay, and if you feed yourself with the idea of lectins affecting you too, then you will remain a strong “barn girl” – the best women on the planet! Thanks PS – I assume Dale is a woman but if it isn’t, it will still keep you strong.

      1. making me laugh this morning with your final comment! Thank you, I need it. I am now visiting a barn where a former student of mine is a manager, and where a former horse of mine now lives. This is a beautiful barn, and all but two of the horses are sleek, well muscled, active with their people, obviously happy. The two horses that do not fit this description are owned by the same woman, another former student. And one of those horses used to be mine.

        These two horses have no muscle at all. They are thin and have a hard time breathing. They move as though their bones hurt. One is 22 and the other 18. When the 18-year-old left me three years ago he was sleek, bonny and full of life and energy.

        Their owner has been consulting a nutritionist and took them off all grain. She “detoxed” them for several months, during which time both would reportedly lie down in the pasture and be almost unable to get up. The barn manager and other former students who keep their horses here report having tried hard to get “Shannon” to feed the two horses enough at least to survive, but she was adamant that the horses needed to be off all grain and fed minimal amounts of beet pulp and a lot of herbs., and alfalfa.

        I spoke with her yesterday and said that if “my” horse doesn’t improve very quickly, he will need to come back to me. She agreed to put him on Triple Crown low starch.

        These horses are on beautiful grassy paddocks 24/7, with a picture book barn to retreat to in bad weather. The barn manager and the barn are what people dream of for their horses. I am worried because a nutritionist has advised Shannon to go grain-free in a way that is obviously bad for the horses, and this has led me to be dubious of grain-free diets.

        Any counsel?


        Dale (yes, female)

        1. Grain free means avoiding the plant proteins (lectins) that are causing disease in horses. They also are part of the reason why protein isn’t absorbed. An altered gut pH and thus altered normal gut microbes also cause protein deficiency. Add to this the lectins blocking the uptake of glucose in muscle and you will get a wasting of muscle. There is also evidence that certain lectins block the signal to form fat which leads to a poor body condition score.

          Grains include corn, oats, wheat, wheat bran, wheat middlings and other words found on the back of the feed bag. I would believe that sugar beet pulp may adversely affect some horses too.

          What needs to be added is a broad variety of proteins. Unfortunately most people with weight loss in horses add grain back into the gut which causes more inflammation. This leads to the formation of fat making the horse “look good” but doesn’t really help the horse.

          The “beautiful grassy paddock” is often misleading. Look at it this way. The grass in the paddock offers only one source of protein, if any. You would not be able to live a healthy life if all you ate was one source of food. Adding a protein supplement like ProAdd will help most horses much more effectively than adding grain.

          Please read all my articles and be patient as I add more. Those clients who have eliminated grain and added protein are seeing dramatic changes. Maybe by the end of the year I will be able to make a nutrition course for everyone to easily access this information. Thanks

    1. Please read my articles at https://www.thehorsesadvocate.com/chronic-protein-deficiency-in-horses/ and https://www.thehorsesadvocate.com/horsetalk-chronic-protein-deficiency-in-horses/

      Also remember the reason behind the chronic protein loss which includes leaking gut from inflammation caused by grains and lectins. Therefore age related diseases including swayback my be secondary to CHRONIC protein loss. Lectins may also block glucose uptake by muscle leading to their chronic reduction in size and strength leading to swayback and kissing spines. All a hypothesis but worth looking at because no one is giving me a reasonable answer to these issues.

  11. Oats, either whole or rolled, have been fed to horses for a long time. My grandfather fed them in the 1950’s. He was an old time Montana horseman, who started working with horses when he was 12. You will find reference to oats as horse feed in the old texts from the 19th century. I agree about there being a lot of things in modern formulated feeds, like soy and wheat, that are not great for horses. That’s why I went back to an old school diet of hay and a small amount of whole oats and barley for my working horse. For a pasture pet or lightly used horse, I would not feed oats at all. For energy for a working horse, oats are very old school.

    1. I agree about oats – in most horses. But the point of lectins is that it is the introduction of grains in the past 1000 to 2000 years that are considered “new.” While some horses have a tolerance to some lectins, not all are free of their effects.

      Melissa’s horses went grain free here and after all problems resolved, she added back 2 cups of oats a day. All horses returned to having squirts. Removing the oats returned the horses to normal feces with the exception to one. That horse needed the red mineral salt block removed to have her manure return to normal.

      The point is this – some horses are more sensitive than others. Treat all horses this way. Return them to a diet they were conditioned to for tens of thousands of years. When the gut has normalized, then add back one additional ingredient and wait 2 weeks and observe closely. If oats are OK for your horse(s) then keep it in the diet IF they need it.

    1. Good question. If there are no other sources of plant proteins (lectins) other than grass or hay then re-do the insulin test. Be sure to fast her, then dose her with a sugar challenge (Kayro Lite) and take another blood at 60 to 90 minutes later. Insulin levels will vary for so many reasons. But if my hypothesis is correct, then if all adverse lectins are removed and at least 6 weeks have past, then I suspect that the insulin levels will return to normal.

      Other ways to determine if lectins are affecting cell access to insulin is to look at the body fat. Many IR horses have excess fat and after removal of inciting grains and feeds (supplements with wheat middlings) the underlying lack of muscle with the associated poor top line makes the owner run back to feeding grains to fill in the gap with fat. OR, maybe your horse is a hard keeper and removing grain starts to gain significant weight.

      Let us all know if you retest for IR in your mare. We all would like to know. But be sure to make sure there are no carrots, treats with grains or sugar filled red mineral salt blocks in the barn. Thanks!

  12. This is fascinating. I did your no grain challenge with my 17 y/o QH. He had anhidrosis and the summer months were miserable for him. He started sweating on day 3 and has been sweating ever since. At first it was somewhat patchy sweat, but now he has totally normal sweat patterns. He also had chronic diarrhea of almost a year’s duration. Since going to a grain free diet his diarrhea has totally resolved. Totally. This is a horse who was only getting the tiniest bit of grain. He was on a ration balancer and a gut supplement that included – you guessed it – wheat middlings and corn distiller’s grains.

    I am a believer. I personally will never feed grains again (and truthfully, I didn’t think I was feeding any before, to tell the truth). There are so many hidden grains in common horse feeds and supplements. Thanks so much for your work on this. Hypothesis or not, it has changed my horse’s life for the better.

        1. Soybeans and soybean meal are two different things. SBM has had the hull removed, the oil extracted and has been heat processed to denature certain enzymes while not destroying the amino acids it provides to the horse.

          In my experience SBM has not had an adverse effect on horses due to lectins. In addition, horses have eaten legumes for a very long time so their lectins are tolerated whereas humans are not legume eaters and are therefore susceptible to legume lectins.