Hormesis, Hay And Horses

(This blog’s header photo is of a modern 6 wheel tractor tedding the hay field before baling.)

In our Facebook group, “The Horse’s Advocate,” a member had a concern about her horse. The “diet” is feeding only pasture and hay, salt and water plus the addition of soybean meal (SBM) to replace the lost amino acids. Here is her post:

My horse just came down with a bad case of grass founder on all four feet for the first time….I have been doing this diet for a year now…got her off of grass and feeding grass hay ( Bermuda & orchard/fescue hay)….she loves the SBM but should i cut it out or maybe decrease?

The following will be a long and scientific answer but in a nutshell, horses need hormesis.  This is the cellular process of resting which helps to clean up cellular debris, remove damaged cells and help the mitochondria switch their fuel source (mitochondrial flexibility). PLEASE read this entirely even though it will sound too far advanced for most of you.  I will summarize along the way in the gold shaded sections and at the end introduce you to a theory of why horses are getting laminitis even though they are off of grain.

The Key Point

The key point of this article is that any animal, (humans, horses, dogs, gerbils) who eat glucose in any form (starch, soft drinks, candy, beet pulp) in excess of their needs on a DAILY basis will become inflamed at the cellular level, develop metabolic syndrome and become ill in one way or another.  Obesity is evidence of inflammation and chronic protein deficiency is secondary to this (sarcopenia in humans or poor top line / hay belly in horses – same thing).

Current research in humans and lab animals have discovered the development of an enzyme called aldose reductase in people and animals who eat abundant glucose every day of their lives.  Many enzymes are developed in animals when certain continuous intake of food require the animal to take action.  An example in humans AND IN HORSES is the development of alcohol dehydrogenase when alcohol intake is daily.  We did this study on ponies in the 1980’s at Cornell because research on liver disease from hepatitis had lots of money.  We fed them 100% (200 proof) alcohol in their meals and measured for alcohol dehydrogenase which was absent at the start of the test. This enzyme is not in children or adults who don’t drink alcohol.  Alcohol is a toxin to the body (sorry folks!) so the body develops this enzyme to turn the alcohol into water.  This is observed as “tolerance.”  When I drink one cup of my wife’s home made, hand whipped egg nog on New Years Eve I become goofy and with 2 cups I’m asleep because I don’t drink alcohol any other time.  

Aldose reductase is a responsive enzyme developed by the body when glucose intake is daily and non-stop year round.  All foods act as signals and the signal of continuous glucose intake is that winter is coming.  Remember all starch is a chain of glucose molecules (https://theequinepractice.com/decomplexicating-equine-nutrition-grazing-not-browsing-part-1/).  Starch is found in growing plants but is gone in dormant plants especially after rain or melting snow.  When food with starch is consumed, the signal to animals (in this case horses) is that winter is coming and the response is, “We need to store more fat!”  The process of making energy within the cell changes and so does the fuel.  Aldose reductase converts glucose into fructose.  These are both sugars but cause a different route in the metabolic pathway within the mitochondria.  This alternate route is inflammatory but is necessary as it is usually temporary.  Winter is followed by spring and food becomes abundant once again.

Glucose is the sugar of starch found in grains and in the nonstructural part of plants.  Fructose is the sugar of fruit but it is now discovered that animals can make fructose when they need to add body fat for winter.

Glucose And Fructose

First let’s describe glucose and fructose.  Both have 6 carbons, 12 hydrogen and 6 oxygen atoms.  Pretend you are joined by 5 other people and you form a ring by holding hands.  This represents the 6 carbon ring structure.  Off of our backs like wings are 1 oxygen with 2 hydrogens.  This represents the glucose molecule C6 H12 O6.  If one person is removed from the ring then it is now a 5 carbon ring.  The displaced person grabs onto someone’s belt behind their back so they are still attached to the molecule but they are no longer part of the ring.  This is fructose, a 5 carbon ring structure with the 6th carbon attached outside this ring.

When glucose enters the metabolic pathway (the Kreb’s cycle) it causes ATP (adenosine triphosphate) to lose one of its 3 P (phosphorous) atoms to become ADP (adenosine diphosphate or 2 P).  It then does it again to become AMP (adenosine monophosphate or 1 P).  This process is conservatively limited by the enzyme phosphofructokinase so that only about 10% of the total ATP is used.  Beyond this point mitochondrial exhaustion begins (glucose metabolism is turned off and glycolysis is started) and the mitochondrial metabolic pathway pathway is limited.  An enzyme called AMP kinase is triggered which adds back the P atoms so that the AMP becomes ATP again and ready for the next use.  A side note here.  The drug metformin enhances this AMP kinase and is used to increase intracellular ATP thus countering mitochondrial exhaustion.

When glucose is the fuel, energy is created by the engine inside the cell (the mitochondria).  A recycling program then takes over well before it is needed to restore the chemicals needed to make more energy so the cell is always ready.

But what happens when fructose is used as the fuel?  After the ATP is converted into AMP with the loss of the 2 P’s and the creation of energy, the path goes in a different direction:  

1) The enzyme used to digest fructose (fructokinase) causes up to 50% ATP depletion (greater mitochondrial exhaustion).  

2) The loss of ATP causes hunger and thirst and increases body fat (energy storage) and glycogen (glucose storage) because glucose is no longer metabolized by the mitochondria but rather through glycolysis which does not use oxygen.  This is a survival mechanism in all all animals facing starvation with the end result of increased body fat and the start of metabolic syndrome.  The excess glucose from starch has to go somewhere as it is not being used and the best storage for it is body fat and liver fat (leading to non-alcoholic fatty liver disease in humans).

3) The satiety hormone leptin (note – not lectin) is blocked by increased glucose intake further increasing hunger and food intake.  The point here is that as the energy factories are shutting down, the continual intake of sugar needs to be stored because when the food stops (winter), the animal will need to get the energy from somewhere.

4) The last point here is that instead of ATP kinase putting the P atoms back onto the AMP molecule, the enzyme AMP deaminase is used turning AMP into uric acid (UA).  This is significant in humans and in lab animals studied because UA is the cause of inflammation in the kidneys and the islet cells of the pancreas.  What does this do to their health?  A lot!

When fructose is the fuel, energy is still created inside the cell but the reserves of supplies are greatly reduced AND the recycling program shuts down.  In addition another chemical is produced (uric acid) that is not normally found. This is OK in a short term situation such as a season but when it continues, it definitely effects the health of humans and lab animals and, I presume, horses too (but nobody is researching this in horses).

The islet cells of the pancreas make insulin.  When inflamed by uric acid, the islet cells make less insulin with subsequent insulin resistance and type 2 diabetes in humans (from the paper “The association between elevated serum uric acid levels and islet β-cell function indexes in newly diagnosed type 2 diabetes mellitus: a cross-sectional study”  –  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846453/  –  The conclusion is quoted here:  “In our study, insulin resistance and insulin secretion increased with rising serum UA levels in both men and women.”)

UA also inflames the kidney which is the regulator of blood pressure (hypertension).  There is a direct correlation between high blood UA levels and hypertension in humans and in lab animals studied.  What this means in humans and in all animals tested is that a continuous intake of glucose throughout the year causes higher fructose in the diet.  This causes high blood uric acid levels which leads to insulin resistance, high blood triglycerides, fatty liver, obesity, metabolic syndrome and heart disease associated with hypertension.  To drive home this point, when animals are given a medicine that blocks the enzyme that creates fructose from glucose OR when they are placed on a very low glucose and zero fructose diet, the hypertension and all the signs of metabolic syndrome are reversed and normalized!  Calorie restriction is what this is called in humans and is the leading theory behind increased longevity and more importantly, an increased health span.

Reducing the availability of starch and restricting it to only what the horse needs to survive the work load and the seasonal elements will lead to the elimination of inflammation which is at the heart of almost every problem we see in our horses.

Now The Hard Part For Horse Owners

Hay is last summer’s grass.  In the 1950’s in the industrialized nations very few people owned tractors.  Grass was cut with mowers pulled by draft horses, picked up by pitch fork, pulled into barn hay mows with a claw on a rope using pulley systems and finally distributed in the loft by hand and fork (search on YouTube for “making hay with horses”).  In the 1960’s the US started the Eisenhower Interstate system of roads (https://www.fhwa.dot.gov/interstate/history.cfm).  By 1970 hay was being made into bales and distributed by trucks along high speed roads to small distribution centers we called farm stores.  The concept of horses eating hay then is only about 60 years old.  Originally hay was used to feed livestock during the hard times of winter to help them survive.  Now horse owners believe that hay is a staple and must be fed ad lib during every hour of every day.  While I have been one of the biggest proponent of feeding horses continuously as suggested by all horses lacking a gall bladder (very few animals are born without this), I believe I was wrong.

It has been demonstrated by the observations of Dr Katherine Houpt, VMD (Cornell professor emeritus) that horses chew between 10,000 and 40,000 chews per day.  With the assumption that 1 chew equals 1 second, this means 10,000 to 40,000 seconds per day are used to intake food.  There are 86,400 seconds in a day.  Using math, a horse is then only eating between ⅛ and ½ of the day.  While this makes logic for me I decided to dig deeper.  There is science behind what happens when we do not eat.  However we first need to assume that every cell in body (all animals) requires energy every moment of life – like a car needs fuel converted into energy to run or it just stops.  We must also assume that all animals don’t take in the raw materials constantly but they go through a process of taking in a meal then when they are not eating, having these raw materials go through the process of digestion into fuels, transport and distribution of these fuels, consumption of the fuels and storage of any unused fuel.

The creation of energy by the cells happens during every moment of life.  Taking in the materials (food) needed to make fuel for this process is intermittent both during a 24 hour period AND during a 365 day year.  To buffer this inconsistent intake of food the body stores fuel as body fat.  The more food taken in beyond daily needs the more body fat that develops.  When this occurs every day and year round, the bad side of things occurs such as disease.

For this part of the discussion we will call the mitochondria of the cell “the factory.”  Fuel goes in and energy comes out along with waste.  The better the fuel the less waste and the less work the cell must do to clean up.  But with more waste the clean up crew starts to complain.  With more complaining, management restricts the tools needed to clean up.  Why? Because management is too busy worrying that winter is coming.  They have too much glucose so they start to change how energy is created as they look for ways to store the excess.  They even start to convert the amino acids into more glucose because the danger signs of a very long winter (an ice age) is coming.  Survival is the highest priority while clean up, maintenance and repair are low priorities.  The means justify the ends.  We will die trying to save the ship.  Etc…

Normally during winter when the availability of glucose diminishes to near zero the cell starts using the more efficient fuel of fat (https://theequinepractice.com/decomplexicating-equine-nutrition-part-7-the-high-fat-diet/).  The horse takes fat stored as body fat and converts it to ketone bodies which are 20 to 28 times more efficient in producing energy with a lot less waste.  The clean up crew goes to work with vigor.  After all, if there is no end in site to cleaning up horse poop with no time left to ride then what is the incentive to keep working?  But with less poop the cleaning becomes fun, right?  With less worry, management has time to bring you coffee and food for your morning break!  Keep dreaming….

Now that there is extra time and energy within the cell, maintenance and repair become a priority.  This is called hormesis.  The cell uses many techniques to repair things and one of those is called autophagy.  “Auto” means self and “phagy” means eat.  The cells literally eat all the waste material and remove it from the cells.  Another process is called apoptosis which is the scheduled death of a cell – like euthanasia of a very old horse unable to get up off the ground.  There are many more processes used every moment to repair damaged proteins (heat shock proteins) and DNA and RNA (sirtuins).  But let me stay with the simple explanation of hormesis and horses.

In winter, horses are supposed to lose their body fat while maintaining their muscle.  When we see this fat loss we need to say, “My horse is repairing and maintaining and will remain healthy and sound because I am seeing hormesis at work.”  If winter becomes harsh with very low temperatures and unbearable wind and snow then add the hay.  That is what it is for.  Otherwise being a good horseman requires us all to acquire a fine eye for when to add food beyond what they are finding in the pasture.  As good stewards of our horses we need to recognize the importance of hormesis and know they need this metabolic rest period seasonally.

I can hear all of you say that you have no pasture.  I see that.  Adding hay then is a requirement but don’t feed it 24 hours a day.  Limit it to what the horse needs to maintain their body weight.  For all who are competing, use your eye.  As the work load increases then add more energy.  About 100 years ago the work required of horses to plow and harvest for all the people moving to the cities was life threatening to the horses.  They lost too much condition so farmers started to add grain to compensate.  Does your horse work that hard?  Then adding grain in the form of whole grains probably won’t bother them as they are consuming the excess glucose and NOT triggering the production of fructose.  But if your work load is less, the need to feed glucose 24 hours a day and 7 days a week is not only unnecessary, it is also harming them at the cellular level.

The availability of food for horses living in nature ebbs and flows.  The body needs the abundance of food to prepare for the time when food is scarce.  They build reserves with the excess food knowing that tough times are ahead so they are willing to pay the cost of doing this (inflammation).  When food is scarce (winter), the cells clean up and repair.  This needed repair period is missing in horses kept in the flow state of abundant food availability – and our horses are becoming ill from it.


Carbohydrate dependency (https://theequinepractice.com/decomplexicating-equine-nutrition-part-6-carbohydrate-dependency/) is the root cause of ills and unsoundness in horses today with the secondary development of chronic protein deficiency (https://theequinepractice.com/decomplexicating-equine-nutrition-08-**the-importance-of-protein/) that I talk so much about.  It is very important to understand that if glucose is fed continuously, the amino acid deficiency will be more difficult to restore.  In laminitis, feeding soybean meal will help to restore the connections between the hoof and coffin bone.  But I think it is more important to eliminate any inflammation first and foremost.  From current research in humans and based on what I have said above, I have a hypothesis.  There is so little known about uric acid in horses but what we do know is that the hooves are a vascular bed of fine capillaries.  If UA causes inflammation of kidneys with secondary effects on blood pressure then would it make sense that UA also causes inflammation with the capillary bed of the hooves?  The same thought of inflammation of the islet cells and the increase in insulin resistance (IR) may also be associated with this very fine mesh of blood vessels.  I am sure that the chronic protein deficiency leads to decreased cystine disulfide bonds in the hooves making their structure and attachments weak.  Therefore it is very important to replace this lost amino acid through the addition of methionine (which converts to cystine and makes up 26% of the hoof).  However, in every case of laminitis there is usually insulin resistance. I believe that IR is secondary to the increase of blood uric acid  (this may be a new idea in the horse world).  High blood UA is directly related to the activation of AMP deaminase that converts AMP into more UA.  The increase of AMP deaminase is directly related to the increase in fructose which is made from the conversion from glucose by the enzyme fructokinase which is developed in animals on a high glucose diet.

Feeding glucose (starch) every day of the year leads to insulin resistance, metabolic syndrome and hypertension in humans and in other mammals tested.  This is probably all due to the new discovery that glucose is converted into fructose with the production of high uric acid in the blood.  This inflames the kidneys and pancreas with subsequent illness.  Testing in horses has not been done but I propose the possibly that this same process leads to the inflammation of the laminae of the hooves.

Excess glucose > conversion into fructose > increased blood uric acid > IR, diabetes, hypertension, fatty liver, obesity and other signs of metabolic syndrome.

I hope this lengthy discussion will help you understand why your horse foundered on grass.  There is so little known about these enzymes and UA in horses and the role in laminitis.  I think this will help you look at it from a fresh perspective. It has for me as these are relatively new findings over the last 10 years of research and NOT in my text books in the 1980’s.  We all know there is an epidemic of obesity, diabetes, metabolic syndrome, non-alcoholic fatty liver, dementia and heart disease in humans.  We also are seeing obesity and metabolic syndrome in our horses in levels I did not see 50 or even 30 years ago.  And it is getting worse.

 Read these and blogs from others.  Avoid agenda driven information where they are trying to sell you something.  What you will find is that simplicity works in most cases – that pulling teeth is a last resort.

I truly hope your horse fully recovers but you must decrease active inflammation and then remove all causes of future inflammation.  This will require you to rethink how you are feeding your horse and throwing out all you were taught as it is not working with this horse.  Other horses may be OK with feeding hay every day or even grain but more and more horses are being pushed to the edge.  I hope this long winded discussion will let you know that at least in humans, the answers to metabolic syndrome seem imminent.  Pfizer is working on a drug to block aldose reductase which will soon be released.  I can see it being used in horses.  Allopurinol will block the production of UA from AMP and metformin will encourage the phosphorylation of AMP back into ATP.  Some vets have tried these medicines but there are not a lot of qualified studies using them in horses.  Be sure top ask your vet about them as you proceed.  Thanks for being a part of this group and searching for answers.  Doc T

Comments 31

    1. Post

      We don’t have good data about horses other than measuring UA in exercising horses. However the process seems to be the same in all mammals according to the research being done in humans and lab animals.

      AMP normally is recycled into ATP to “recharge the battery” so to speak. But when fructose is used for energy production enzyme AMP deaminase converts AMP into uric acid.

      In humans, uric acid is associated with gout. This is when UA forms crystals which settle into joints. Foods high in purines also cause high UA. Purines are foods high in DNA and RNA such as meat, shellfish and yeast (think beer). However AMP is actually the best representation of a purine. And many horse feeds have yeasts added as a “probiotic.”

      So the high UA in tested mammals come from 1) the food we eat and 2) fructose. In humans table sugar is half glucose and half fructose. High fructose corn syrup is 60% fructose and when in liquid form, the fructose swiftly moves to the colon where it appears responsible for the formation of colon cancer.

      Finally, the most revealing evidence that fructose is causing problems is that in humans AND ALL ANIMALS TESTED, the removal of fructose from the diet eliminates metabolic syndrome, obesity, IR, diabetes and hypertension. So why not in horses?

        1. Post

          I do not know of horses eating fish though I did see the YouTube of the Icelandic horse eating fish whole as fast as they could put it in the horse’s mouth. Horses are hind gut fermenting animals specifically designed to eat cellulose.

          As far as humans go, I am not an expert. However shrimp and beer should be eliminated if you have gout. Eating raw or grilled fish have more advantages than disadvantages but all meat are high in nuclear material which are the definition of purines (UA being a purine). This new information presented here would also have us all eliminate all fructose as well as diminish or eliminate starch to improve our blood UA levels.

          And there is also evidence that if you are dehydration to any degree and you eat salt before rehydrating will trigger Aldos reductase and convert glucose into fructose. In other words, if you eat the salty fast food burger AND the salty French fries (high glucose) and THEN drink the soda with sugar or high fructose corn syrup it is too late. If you are thirsty you are already converting that meal into fructose with metabolic syndrome and hypertension following.

  1. Thank you for this blog….i will need to reread it tho….and thanks for answering my questions….

  2. A friend mentioned that her gelding who is on The Diet is urinating a lot and seems to need additional calories. Would urinating a lot be any indication of excess UA stressing the kidneys?

    1. Post

      I do not know but humans excrete about 70% of their UA via their urine. This is due to a genetic mutation in humans where UA cannot be further oxidized by the enzyme uricase. Therefore there is more to excrete. This lack of uricase has not been demonstrated in other animals but the assumption is that it is still active. Therefore there should be less UA to excrete. But on the flip side the research also shows that there is an increased production of UA due to the things I discussed in this blog. Again I do not know if there is any evidence that there is an increased osmotic draw of UA into the urine. You will need to ask someone in this field.

      In the meantime your friend should have a urinalysis performed and discus the results with her vet.

      “Additional calories” is a common thought as a horse that is using body fat for energy will lose the fat and reveal the lost muscle. However these horses are usually lively and willing to perform their tasks. After the excess fat is removed and the amino acids / top line restored the diet can be adjusted using the eye as well as knowing the season (middle of winter or middle of summer).

      1. Great information Doc T ,once Java was off the grain there was a difference .No stocking up in hind legs,better top line.thanks to you and Kathy,more people should be educated on this and to stop giving sugar to their horses ,Thanks again for the wonderful information you share😀

        1. Post

          You’re welcome Rochelle. More and more people are listening and for those trying to understand why it works, this blog attempts to fill in the gaps. Hopefully a researcher will take the information we have today and discover all of this to be true in horses with hard data. But that will never happen because there is no money in it.

          Until then all we have are the hundreds of comments on these blogs and in the FB group “The Horse’s Advocate” where there are so many positive testimonials. I am grateful to all who have listened and tried removing the starch in their horse’s diet and have realized with their own eyes the improvement in their horses. Thank you ALL, Doc T

  3. “Other horses may be OK with feeding hay every day…” You got me on this one, Doc T! I always assumed if your horse is overweight that hay would be the proper diet, eliminating feeds and limiting pasture. Am I wrong? Sorry if I missed this point in your article, although I do understand the idea that it’s ok to let the stored fat (clean-up crew) take over periodically.

    1. Post

      Remember that hay is last summer’s pasture and depending on how well the process of making that hay, the glucose of starch will still be significantly in it. People for a long time were concerned with the depletion of vitamins in the hay but this is not really a concern relative to the starch (non structural carbohydrate or NSC). If you have a fat horse and you feed starch in any form day after day throughout the year, the horse will never lose the body fat.

      We have been hearing more and more in nutrition of ALL species that the food eaten should be only food that can be found in the environment at the time of consuming it. For example, in humans it is becoming common not to eat fruit or vegetables unless it was harvested that day. Of course this is the way it was before refrigerators and preserving techniques were developed. The same is true for horses.

      It may me more recognizable to think that grains are only available during a short period of the year. We forget that hay not only is last summer’s grass but the fact that we have hay is only a recent technology. “Recent” means that 60 years ago there were no highways, large trucking outfits, tractors, baling machines, hay distributors or feed stores. Most horse owners only had pasture.

      All animals need time off from digestion of food. As the cells no longer are being fed glucose from the starch intake for the fuel, they become “stressed” forcing the body to switch over to an alternate fuel which is the stored fuel in the form of body fat. Remember that both sugar AND fat are made of the same elements – carbon, hydrogen and oxygen. They are put together differently and the body uses different processes to turn these fuels into energy. This ability to use different fuels is called “mitochondrial flexibility.”

      When the cell is being fed a restricted starch intake (when they are forced to use body fat as the fuel) then the cell is running more efficiently. This is when “hormesis” occurs which makes the cell and the overall body healthier.

      The point of this blog is that horses need time away from starch. They are really efficient at digesting cellulose with their hind gut which allows them to survive on low starch / high cellulose dormant pasture. However, when there is abundant starch in their feed every day (grains and hay), the horse doesn’t need the fat formed from cellulose. The excess fuels (both starch and fat) still need to be stored if it isn’t going to be used. The result is that horses develop excess body fat. In addition, the horse goes into survival mode from the excess starch intake by converting the glucose into fructose which 1) causes mitochondrial exhaustion, 2) causes excess amino acid consumption / chronic protein deficiency, 3) creates insulin resistance and 4) creates the signs on EMS or Equine Metabolic Syndrome. All of this is done to survive the upcoming long winter the excess glucose is signaling the body to prepare for.

      Subsequent to all of the long term and never ending metabolic changes is the development of illness (Cushing’s disease, unthriftiness, colic, old age), unsoundness (laminitis, connective tissue disorders), behavioral issues (hyperactivity, poor work ethic, bad behavior) and a loss of money and time invested in the purchase, maintenance and loss of use of a horse not being allowed to eat like a horse.

      We all need to re-think our daily use of hay in feeding horses. Individuals, use of horse and the current season all play a factor and we need to look at our horses with this new and fresh perspective that hay, when used properly and judiciously is good but when just given ad lib may be doing more harm than good.

    2. What does one do if all they can feed is hay? That’s all we have in S. California. We do not have pastures or grazing that would allow a horse to live on it. So in my case, my IR horse eats teff grass and alfalfa with no grain products. She was managed within normal numbers for over a year but came out of spring with higher than normal with eating the same. I can not test every batch of hay I get, I know it varies but I buy in 10 bale increments. All her regular blood work is fine, no issues there.

      1. Post

        Feeding hay has many of the ingredients found in grass so feeding any forage to an IR horse needs to go with caution. It actually takes a lot of effort to look and adjust weekly if not daily.

        You need to look for body fat and asses this with the overall health and attitude of the horse. IR, according to this research, is secondary to he daily feeding of glucose with its conversion into fructose. This sets off the pathway of uric acid production with subsequent inflammation of the pancreas which leads to metabolic syndrome including IR. I also believe fructose metabolism is behind mitochondrial exhaustion with secondary protein loss.

        Therefore even if you have no pasture, if you are feeding hay which provides glucose in excess of your horse’s needs then the excess will trigger the conversion into fructose. While this has not been shown in horses (yet), it has been shown in humans and other lab mammals. For me I have trouble finding another reason for the increase in metabolic syndrome in horses since the addition of grains and hay to our horse’s diets.

        Here is an experiment for you in southern CA where there is no pasture. Limit feeding hay to within an 12 hour window even if this thought makes you cringe. Remember that ulcers are caused by a dysbiosis of the gut microflora and not emptying of the stomach. The exception here is if you exercise your horse after an all night fast and before filling the stomach with hay. Don’t do that!

        Be sure to add a protein source if there are signs of protein deficiency (poor top line, poor hair coat, poor hooves, hay belly, connective tissue strains). I have several blogs on chronic protein deficiency. This will help to eliminate food aggression which is not hunger but the more looking for a missing need in their food. Adding the missing amino acids will satiate the horse as well as minimizing the excess glucose in the diet. The goal is to attain slow weight loss over the summer and through the winter. The test is for a normal blood insulin value next April. Please come back and let us know how you did.

  4. This is great Info. I know I will get the following from clients: “my horse has ulcers and I try to give him free choice hay so that he can keep something in his stomach to buffer the acid”. (This is obviously going to be for those who have horses that are stall kept)

    1. Post

      Filling the stomach with hay BEFORE EXERCISE will reduce the splash of stomach acid onto the non-glandular portion of the stomach according to the vet who helped develop Gastro Guard. He said this to us in a small meeting of vets back when Gastro Guard was first introduced. At that point, gastric ulcers were only found in TB race horses.

      Today ulcers can be found anywhere in the digestive tract of horses and humans (small and large intestines as well as the mouth and stomach). It is now well known that the cause of digestive tract ulcers is from a dysbiosis – where the normal microbes of the affected area are no longer healthy or have been replaced with other bacteria not normally found there. Restoring the normal microbiota restores the lining of the gut. Get the bacteria right and the ulcers will be gone.

      Next time someone says, “My horse has ulcers,” ask them if they are talking about gastric, duodenal, colonic, anal, or oral ulcers. That will get their attention. Then tell them it is not feeding hay 24 / 7 but eliminating the inflammatory ingredients including 10 carrots a day or the red mineral salt lick that will heal the ulcers. Or, you can just ignore them and wait for someone willing to listen and change from what is NOT working to something that might help. Anyway, thank you for your help and for your understanding. Doc T

  5. In the ECIR group, it is thought, if your horse has PPID, pasture, fresh grass, is not to be taken in. Two horses here tested positive, ECIR. One tolerated Prascend, the other did not, at all. Severe GI disturbances that did not go away even at 1/4 dosing after pulling him off of it for a week. I asked the group about the intermittent fasting I do to promote autophagy and regeneration for the horses. It was a clear NO as feed back, as I was told that would promote ulcers. The idea of free choice hay and the horse will self regulate eventually came up. The Arab on Prascend has lost all fat pads acquired in his 22 years of life, and the other horse, a large WB, age 21, has too, but is only on CBDs, 100% organic hemp, at a increased dose. (TRH respectively was 1000 and 600) Both horses have shed out this year. They do get turned out for 30′ with the other two, and there is a lot of running around. The WB is still being ridden. I still am concerned about inflammation though, and the idea of leaving them on pasture goes against all other data coming thru the ECIR group. You seem to be recommending no hay. We feed Timothy and measure it out for each feeding. 14lbs/day for the small Arab, and 17lbs/day for the 1200 lb WB. I am already in violation of the Rx with the turnout, but it is so social, and seems to be a ok on the hooves. More than that and I do see changes. Please advise. Thank you!!

    1. Post

      I did not say that pasture would be OK for horses with IR or Cushing’s or laminitis or any other condition where adding the starch of pasture would worsen their condition. What I did ask was why are we feeding last summer’s grass all year long or this summers hay while there is summer pasture? If hay is fed in the winter then the period where a horse would decrease their starch intake would be lost. This would prevent hormesis as well as promote the signaling that winter is still coming. This would lead to additional development of metabolic syndrome which includes IR as well as mitochondrial exhaustion causing chronic protein deficiency.

      Please read my reply to another comment on this blog about ulcers in the digestive tract of horses. Horses will not “self regulate” food intake if they are missing something in their diet. That “thing” they are missing apparently is protein as horses fed adequate amounts of all of the essential amino acids eliminate their food aggression.

      My belief is that Cushing’s disease is a neurodegenerative disease prevented by avoiding the loss of the proteins needed to prevent the neurodegeneration in the brain. Prascend is a replacement of the dopamine neurotransmitter (a protein). While the actual cause is still unknown, many horse owners, with the help of testing through their veterinarian, have been able to normalize the horse’s cortisol without medication by removing inflammatory foods and replacing the lost amino acids.

      There is abundant evidence that metabolic syndrome in humans and other lab mammals tested (and there I am assuming horses too) is secondary to the continuous feeding of glucose with the conversion of glucose into fructose. Looking at the feeding practices in today’s horses I also see the continuous feeding of glucose not just in grains but in the abundant amount of hay fed. I wanted to draw attention to when hay was first made available to horse owners. It was fed only in the winter when they needed it.

      Please don’t confuse my thought of NOT feeding hay when pasture is available to preferring pasture over hay for all horses. This will be ill advised for most horses especially if it is a novel idea. My point is really this. Our horses need glucose to replenish the glycogen stores used throughout the day as well as fuel the metabolic processes in every moment of life. However the purpose of storing fuel for winter in the form of body and liver fat is necessary when there is no other food available to eat. While horses did migrate, the grasses still went through a dormancy period everywhere they lived. This period of scarcity was a welcomed period in cellular health when the cells could do their maintenance.

      For horses in the northern hemisphere, it is the middle of summer with winter 6 months away. Horses with EC and IR need to be cautious now as they tread lightly through summer pasture and abundant fresh hay. But I can see no downside to limiting these now to maintain their weight then continue to restrict through the winter to kick in hormesis and body fat reduction. Those of you in the Southern Hemisphere are in mid winter where restricting access to hay and providing limited turn out of dormant grass will encourage fat loss. Adding a protein source such as soybean meal will help to satiate them reducing their desire to eat which in turn will rest the digestive system and allow the cells to use ketone bodies for fuel.

      Owners who have limited the intake of food in their horses to just winter pasture through the winter have reported the loss of body fat and with the addition of SBM they have reported their horses returning to normal health. However it is hard to change from what we do now to something different. The good news is that this costs nothing to do and you can always revert back to the old way of feeding if you become worried. You can also join “The Horse’s Advocate” FB group to hear what others have been through, their concerns and the results they have gotten. It is a safe and free place to exchange information on this.

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          I look at it as a neuropeptide which is derived from the amino acid tyrosine. Therefore if there is a specific amino acid deficiency then it is reasonable to think that there is no neurotransmitter. Thanks for allowing me to clarify this.

  6. I’m confused by what you wrote. Maybe because of the lack of data to back it up (of course there’s very little funding for equine research). In the north we have no pasture in the winter and in the South we have pasture most of the year. Are you proposing to starve the northern horses by keeping them off hay and grain/fiber all winter, and pulling the Southern horses off pasture in the winter? Wouldn’t this only work for really FAT horses? Wouldn’t the resulting constant ketosis stress their kidneys?

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      You are close. It is not just ketosis as most horses today will continue to be fed especially if winter is severe. The concept here is that the continuous intake of glucose ABOVE their metabolic needs and their need to restore glycogen is still signaling that winter is coming. This leads to more body fat as well as the further development of metabolic syndrome including obesity, insulin resistance, mitochondrial exhaustion and protein loss. It is insidious and at a future point we start to see disease and lameness develop.

      Horse owners need to develop an eye to look for the balance between enough food and too much food. Most look at their water and say, “It’s time to feed the horses.” Little thought is used to avoid this cookie cutter approach to their health. Instead, owners need to look at each individual and adjust their feeding to the age, breed, use, season and any genetic disorder or illness they have. The goal is to determine how much food is needed to replace the lost glycogen.

      With the understanding of how the cells and proteins / enzymes work with the bacteria to convert raw food into fuel and then into either energy or to fuel storage, any horse owner will be able to feed any horse. I often ask how to feed an Arabian, an Icelandic horse and a Mongolian horse all living in Mississippi. The answer is differently but using the same principles of digestion. This blog shows another layer of overlooked fundamentals I touched on a while back in a blog called “Carbohydrate Dependency.” This has more detail but all animals in our domestic world (including humans) are now more unhealthy. With the COVID pandemic it has become obvious to those looking that it is not the virus but the underlying health issues that is causing illness and death. The worst co-morbidity issue is obesity, or as I read today, “Diabesity.” Stopping insulin resistance will thwart COVID as well as laminitis and other diseases of horses and humans.

      My apology for confusing you. While the principle here is simple, most horse owners just want to know what to do. My wife tells me this all the time. So here I’ll do my best. Feed your horses no inflammatory ingredients and limit their forage to the point you see them lose body fat. Then, depending on your goals, adjust what they eat to maintain your goal. For example if they are fat and retired then have them lose a lot of fat over the winter and allow them to spring back in the summer. But if they are competing, their fuel needs will be more so feed them to maintain their condition. Here they will consume their free glucose or they will store it as glycogen. Just don’t give them enough to add body fat because athletes usually have little body fat.

      Remember to restore their lost amino acids. You can’t do a blood test for this but look for a poor top line, a poor hair coat, poor condition of the hooves and the presence of a hay belly. All of these are signs of chronic protein deficiency. Adding this to their diet will help to satiate them as food becomes scarce. (see my blogs on protein)

  7. Your call to not not feed hay 24 hrs a day rings true with our experience. I know many feed with slow-feet nets, but we have not done that, and our horses go for at least several hours at night with no hay. In the summer, they get mostly just pasture, and in winter we plant a small amount of rye for something green to nibble on, plus hay. This past winter, I fed less hay than normal, sort of an experiment, and they looked great all winter. We occasionally feed a supplement (you’ve been so helpful in your blog with helping us sort this out). Our horses are shiny and happy. It will be so interesting to follow future research on this. The interpretation of research results is a tricky art, and we need to be flexible in our beliefs over time. And thank you for reminding us that hay in bales is a relatively new reality. Lots to think about here. Thank you for sharing your thoughts and experience!

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      Thanks for this input. You are helping horse owners reading this to understand the concepts here.

      This blog is full of science and will take several readings to understand it. I read and re-read my notes to write it. It is all relatively new but the way you told us of your experience will help many understand it even if they can’t remember “aldose reductase.”

      Gratefully, Doc T

  8. Update….had xrays done and 6 & 7 degree rotation on front hooves and 4 & 5 rotation on backs….started the DMSO drip today along with 4 grams bute dailey and two 1ml injection of a acepromazine twice dailey….The vet made custom tennis shoes for her…thinks this has been a long time coming…..said we can recoup but will always need a muzzle to graze when that is allowed somedsy….for now, she lives in the barn with hay, water and SBM and her salt until she is sound again

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      Thank you for this update Shelly. Please continue to come back here with updates that will be of interest to all. I am sure everyone here is praying for a full recovery. With your attention and efforts – and patience – I’m sure she will do well. Doc T

      1. Still no real response, meaning hardly walking….my vet even made her some custom tennis shoes which helps her to move some….she is still taking all the pain meds he perscribed along with ulser medicine and acepromazine for blood flow….he said its a long road ahead , maybe even a year to recover but when and if that day comes, she will always need a muzzle and only at night for grazing….she also has thin soles, which i didnt know since shes always been barefoot and never gimpy….she’s my husband’s horse and we both feel her quality of life is gone….with the meds, prone to founder again, muzzle , special soft boots and being stuck in the barn all day, and the possibility of having naviculer ,IR and Metabolic syndrome, he has decided to put her down….this founder has come out of the blue with no prior hoof problems other then a couple abscesses….one day she’s running around, next day she cant walk ….its so heartbreaking to see her this way and in pain…The vet said this has been going on for awhile but we never saw any indications ….meanwhile her buddy, my QH gelding is fine and grazing …I just dont get it

        1. Post

          Just to let all know, the pony, the subject of this blog, became worse, was suffering and was euthanized today.

          All who read this blog will be sharing your loss with you and your husband. The decision to end her life is something many of us have had the solemn duty as owners to do. It is a long lasting sadness I, for one, have experienced too many times.

          The sudden turn from running in the field to being too painful to walk is made worse by the news that this has been going on for a while. Questions arise wondering why the vet or farrier or anyone didn’t let you know this was a possibility some time ago. And why this horse and not your other horse or any other horse you see down your road?

          From reading this blog you can see there is a complicated process that has been developed over a million years to help our horses survive in an unforgiving world. Genes mutate because of signaling from the environment, from viruses that constantly insert “software updates” into the genetic code and by ordinary copying mistakes from incessant doubling and dividing of cellular material in reproducing cells. We assume perfection in an industrial world that offer guarantees and warranties but life is not a machine.

          You may never get a full explanation or a full understanding. However this blog will undoubtedly help others who read it and take the time to change their way of feeding their horses before the hooves start the breakdown yours and so many other horses have gone through. In 1979 I was in the halls of the vet school at Cornell. I was still an undergraduate but I discovered that every Friday afternoon at 4:30, rounds would be help in the post mortem room. I would sneak in and sit among the vet students. Livers, lungs, hearts and skulls lay on the stainless steel tables and the professor, Dr King, described the lesions that killed the animal. On occasion he would have displayed the hooves of horses that had died from laminitis. After a while he began to recognize me and even though he was feared by students who he picked on unmercifully, he never called on me. He looked at me but always passed on the opportunity because I was not a vet student – yet. After rounds one day I mustered the courage to say something to this powerful and world renowned veterinary pathologist.

          “Dr King,” I blurted out in the hallway and he turned around and pierced me with his eyes. I trembled then blurted out, “I plan to figure out why horses founder.” It was only a seed of conviction at the time but after seeing the cut open hooves that afternoon from a pony that had succumbed to it and from experiencing several horses in my life suffer from it, I knew that there must be an answer.

          But I am not a researcher and in 41 years, it seems that few still understand this dreaded condition of horses. As a student I saw the first cases ever recorded of horses (not ponies) coming down with laminitis overnight after bedding on black walnut shavings. About 10 years ago a philanthropic owner down here in Florida funded the biennial laminitis conference and I learned about sugar overload and insulin resistance behind all laminitis cases. But no one could give the molecular or cellular reason for the event. They could easily cause it with both carbohydrate overload and with black walnut shavings and most laminitis studies are initiates with the carbohydrate model.

          This blog has attempted to dig into the cellular reason for laminitis but connecting this to changes in the grass is still needed. The variety of grass available for pasture, I believe, has been genetically altered by seed companies to promote growth in grazing animals used for food such as cattle. The increased starch or possibly the fructans created by grasses exceed the dietary needs of many horses which starts the cascade of events I describe here. Fructan are chains of fructose in plants that help to resist freezing temperatures. Fructans are considered in humans to be a resistant starch that promote the health of the hind gut bacteria but I am not sure of their effects in horses. Whatever the molecular reason is behind laminitis occurring in grasses, there are many horses susceptible to it. It seems unfair that the genetic manipulation through controlled breeding of plants has made beautiful looking pastures deadly for some horses.

          Our condolences to you and your husband. My hope is that someone with research savvy will also read this and help us learn why her suffering occurred. Ending laminitis is still something I want to achieve. Thank you for reaching out with your question a while ago that created this blog. I am sorry we, as veterinarians, still cannot prevent founder from occurring.

  9. Ok, so now what do we do? Do we limit the amount of hay, or cut it out totally? If yes, for how long?

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      All horses need forage to survive. Their intake serves two purposes. The first is to supply fuel for metabolism and to restore the glycogen reserves of glucose. The second is to add body fast for the upcoming winter when food with glucose becomes scarce.

      We now have an ever present source of glucose (starch) in bales of last summer’s grass. In humans we have pantries and refrigerators filled with food and replenishment services that deliver to our door more food. Hay is no different for horses with feed dealers ready to replenish our hay mow with just a phone call and a credit card.

      You need to determine how much hay is needed for an individual horse based on their age, breed, use and any illnesses they have. Then you need to feed the amount of hay needed to maintain their body condition if it is perfect, add more if they need more or reduce it if they need fat loss. There is no test or formula. Just understanding that hay is not a normal feed and that by overfeeding hay throughout the year we are not allowing horses to go through the normal ebb and flow of life. This prevents hormesis which leads to mitochondrial exhaustion, protein loss, etc (see my blogs).

      Some people have reported that their horses only get what is in the pasture all winter with fat loss by spring time. They also say that the horses at that time also look sleek, shiny and healthy with full energy. This is because they have gone through the process of maintenance and repair. Losing fat is not bad but is actually an indicator that cellular health is being restored. Like anyone on vacation finding energy to get back into the game.

      Feed your horses with a new keen eye. It is not a cookie recipe of all, some or nothing. It is a day by day adjustment. Things might look good the beginning of January but then a winter storm come in with an Arctic blast. Your horse will need shelter and MORE HAY! After this though you might reduce the hay and watch carefully the fat covering, the hair coat fullness, the overall health and shine in the eye and determine that all is good with the reduced hay diet. Day by day, spring will come again and the grass will fatten them up again. At that point you do not need to feed hay and they may not even want hay.

      Remember if there are signs of protein loss (poor top line, poor hair coat, poor hooves, hay belly) then add a high quality protein to restore all the missing amino acids. This will really help the horses through the winter months because they will not show signs they are looking for a missing ingredient. This is often confused with hunger.

  10. I am frankly confused by this article. If hay is last summer’s grass, and letting horses forage on pasture is healthier for them, then why restrict hay? Both pasture grass and hay have starch, correct?

    I really need to know how to function on a property with very limited pasture. Both my horses–a mini shetland and a Rocky–improved greatly in body condition on ad lib hay and 24 hr turnout in years past. But this past year, their first year on SBM, both got scary fat on ad lib hay AND SBM. So is the piece I’m missing that with SBM fed daily they no longer need ad lib hay?

    I was forced to weigh the mini’s hay and start feeding it to him only 2x a day in a small hole hay net because he became frightfully fat. But what finally caused both of them to lose weight and lose hay bellies was taking them out in the wilderness for five days where they had only wild grass to eat and they were in work. We just got home and they both look great.

    Right now they are on a hilly track at my home, with access only to sparse native grass, and I’m feeding little to no hay and letting them graze the track down. I do have two small pastures with tall grass with seed heads I could also turn them out on for a couple of hours a day. What do I do when the track is bare, as it will be shortly? I don’t want the small pastures stripped, and they aren’t set up for 24 hr use.

    And what do I do about buying hay this year? The two of them went through 6 tons of ad lib straight grass hay fed in 1″ hay nets this past year. Should I feed much less? How should I feed during subzero Montana winters? They have stalls to escape the wind, and heated water and 24 hr turnout. How do I keep them from getting fat again over the winter when there is no work for them? Is it time to quit the SBM?

    I want my horses to keep a nice BCS of about 4-5, no more. This past winter they may have gotten as bad as a 7 or 8. The Rocky is age 11, 1100 lbs, 15H. The mini shetland is 42″, age 14, and I would guess about 400 lbs.

    Thanks in advance for any further decomplexicating you can offer.

    1. Post

      It is confusing because of what we have been taught ingrained in our minds. then I come along and say what I say and you realize that what you are doing isn’t working. Then you do something else like pasture in the woods and instantly see an improvement. Then the fat returns and is accentuated with the addition of SBM. Wow – enough to spin there head right off the shoulders!

      The ad lib hay is feeding glucose in excess of their metabolic needs every day and that is what this blog is about. The horses continue to gain fat but underlying the fat gain is muscle loss. The cells are not going through hormesis and the mitochondria are exhausted. Because of this the brain signals for auto conversion of protein (amino acids) into more glucose! (see my other blogs or enroll in my nutrition course if you don’t understand this).

      The result of horses converting protein to sugar is that many if not all horses will actually convert the protein fed directly into more glucose. This is the reason some horses get fat with SBM. These horses need to reduce their glucose intake and get back to normal metabolism which requires up to 6 weeks on a no grain diet and reduction in hay plus pasture consumption.

      If pasture is limited then hay needs to be fed. Unfortunately most hay is of one or two types of grasses or a grass plus a legume. These are poor quality protein sources. Worse, many grass seeds have been developed to increase starch production in cattle so they are not the same grasses found in the past or in uncultivated woods. This is why they did so well in very little time. Their microbiota probably also benefited from the diversity found in the wild pasture. After all, we are really feeding the microbes and they, in turn, are feeding us.

      You are correct that this blog is the missing piece – that you need to reduce the hay consumption. They are not self regulating and are over eating into obesity because, 1) The mono-grass hay is developed to have more sugar than wild grass, 2) the glucose intake is continuous causing metabolic syndrome, added body fat and mitochondrial exhaustion with protein loss and 3) the addition of protein as SBM is being converted into glucose before it even enters the body from the digestive track.

      Your goal is to feed the hay in amounts that meet but does not exceed their daily needs. This will be different for each horse and makes having a mini and a horse together difficult. They will maintain their condition without fat gain if you are careful through the summer. Feed no grain, treats or supplements as their microbiota adjusts. Consider revisiting the wild grasses occasionally this summer. Add in the SBM as you notice them stabilize with a little at first and increasing slowly adjusting the hay as you go to maintain their weight. The SBM will help satisfy their hunger. As winter comes along don’t increase their hay unless needed for severe weather. They should lose their fat and go through hormesis so by April they should look and feel very healthy.

Your thoughts are important for all to hear and may help others to learn from your experiences. Take the time to add to the discussion. However due to time limitations I will probably not answer direct questions to me. Thanks, Doc T

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