Metabolic syndrome, insulin resistance, and the horse. An ever present problem, contributing to a high percentage of laminitis cases, which are often seasonally related. In the past 2 articles, I have defined the problem of metabolic syndrome and insulin resistance, as well as raised the questions as to whether or not some ‘clinically normal’ horses may be more susceptible that originally believed. In this article, part 3 of 4, I will discuss newer therapy options, including the ketogenic diet, with specific goals that show promise in the horse impacted by metabolic syndrome, insulin resistance, and laminitis.
When you look at the average horse with equine metabolic syndrome (EMS), insulin resistance, and laminitis, there are often many common denominators. Now, not all EMS horses will exhibit insulin resistance, nor will all demonstrate clinical signs of laminitis. However, a high percentage of EMS horses will demonstrate foot sensitivity or pain, being exacerbated by pasture and other source.
Common Denominators in the Equine Metabolic Syndrome Horse include:
- An overweight body condition (body mass index- BMI)
- A sedentary lifestyle
- Restricted pasture access
- Consumption of ‘low NSC’ grains and trace mineral supplements
- Low quality forage or hay access
The exact cause of equine metabolic syndrome and associated insulin resistance and/or laminitis is unknown and likely there is no ONE cause. Many do associate the condition of EMS to be connected with genetics, and I will fully agree that many are predisposed to this condition if the circumstances are right. In looking at human medicine, metabolic syndrome and diabetes, there are definite lifestyle factors which are in play, which directly contribute to the condition development, and likely open the door for the genetic predisposition to rear it’s ugly face.
Main contributors to metabolic syndrome and diabetes in humans include:
- Excess body weight or obesity (high BMI)
- Sedentary lifestyle
- Poor dietary choices
- Reduced exercise
In looking at these 4 contributors, it is not hard to see that they follow similar lines in the horse which is impacted by metabolic syndrome. Now, one more contributor in human medicine and research is digestive health, with a high percentage of humans impacted exhibiting an imbalance of the digestive microflora or a dysbiosis. This is evident as well in more recent and emerging research in the horse and should raise an eyebrow. However, even then, there is the question of whether this dysbiosis is a primary or secondary event? Either way, it appears to be a player and in my experience, performing fecal cultures on over 400 horses to date, there is a definite problem in the metabolic horse and when measures are put into place, fecal cultures improve on follow up, along with clinical improvement in the horse. Thus, to me, it doesn’t matter whether if digestive dysbiosis or imbalance is primary or secondary. It is a problem and needs to be addressed properly.
The bottom line, as in human research and medicine, there is a definite lifestyle factor involved with the development of equine metabolic syndrome, insulin resistance, and associated laminitis. If we follow recommendations made on the human side of medicine, and apply them to the horse, often the condition quickly changes and the horse improves clinically. However, it is wise to keep in mind that these new lifestyle changes are not a ‘cure’, but more so are a means of helping the body to re-establish balance and harmony with proper cellular function. If you acquire clinical gains by implementing the changes, then discontinue or revert back to prior ways, all positive gains will be lost and ill-health will be present once again. This is due to genetic activation and influence of environment and lifestyle.
Exercise and the Equine Metabolic Horse
In taking these contributors one by one, you need to keep in mind that no ONE thing is going to remedy the problem for your horse, however, every ONE thing can make a difference and create improvement. The one factor that does need to be addressed in almost all EMS horses is exercise. I would have to estimate that over 80% of these EMS horses do not get proper exercise each day or at least several times per week. A high majority of them live sedentary lives, either in a stall, a small paddock, or a dry lot. This lack of exercise creates problems regarding health and quite honestly plays a huge role in creation of the equine metabolic syndrome situation.
If your horse can be exercised, then they need to be exercised. The only restriction here would be the EMS horse that exhibits laminitis or severe foot pain. However, if you apply boots and the horse is capable of work, then in my opinion, this needs to be done. Exercise helps the horse’s body in many ways, from mental stimulation to helping to reduce inflammation, digestive health, and plain caloric burn. It is very, very important and quite honestly one of the main contributors to the EMS condition. Many horses that live an active career in competition are retired, then during that retirement develop a sedentary or markedly reduced exercise level. This then contributes to gene activation and changes in cellular biology, helping to create the EMS condition in the horse.
How much exercise does the average EMS horse require? That is an individual thing, but in reality, any exercise above what they are currently doing is beneficial. So, if a horse is confined to a dry lot and pretty much stands idle picking at hay, then getting that horse to walk 3-4 miles each day (45 mins) is a positive thing. Starting at a very low level is important as most of these EMS horses are not in good body condition or fitness. Beginning with hand walking for 45 mins 3-4 days per week for a couple of weeks is a good start, then working your way up to some ground work such as lunging or otherwise can be done as the horse allows. Again, use boots if needed when foot pain is present.
Keep in mind that the level of exercise is important with the goal of stimulating the body, increasing the heart rate, blood flow, and respiratory rate for a consistent period. This physical stress, followed by rest, is a positive thing for the body as it stimulates many positive reactions on a cellular level. Going for a trail ride, at a walk a few days per month, is not the level of exercise I am referring to. In reality, your horse has a metabolic issue, is overweight, and not physically healthy. This needs to change and the only way to truly do it is by stimulating the body, challenging it, over a period of time with increasing levels of exercise.
Always think of an overweight person, in need of weight loss and improvement of health. A walk around the block once a week is good, but doing 1-3 miles 3x per week is even better. Take it slow and work your horse up to a desired level over time, monitoring them and changing the regimen to suit their needs. Many are stubborn and may just lack desire in the beginning, which is understood, but if you want to help them, improve their health, and lower your veterinary costs….you must push through!
Many times, the exercise factor in the EMS horse’s recovery is our own fault as the owner. The horse is often willing and capable of working or exercise, but we as humans fail to make it a priority or make the true effort due to other time constraints or factors. Look at it as being a win-win situation! Exercising your horse may actually improve your own health and mental well-being!
Diet, Equine Metabolic Syndrome, and Insulin Resistance
The diet is one main contributor to metabolic syndrome in both humans and horses. It is a contributor by itself, and very important, but it also goes along with the other contributors. A poor or improper diet along with a sedentary lifestyle is likely much worse than a poor diet and an active lifestyle. Then again, I’m not sure an active lifestyle in the horse would tolerate an improper diet.
Here are the most common feed regimens assumed by a high percentage of equine metabolic patients.
- Low quality forage
- No pasture or limited pasture access
- Low-starch commercial grains
- Inorganic trace mineral and vitamin supplements
For some EMS horses, this regimen works, but for the vast majority, this regimen is put into place and just ‘maintains’ the horse. This implies that the horse is no better, no worse, and still has periods of flare ups and pain when it comes to foot health and laminitis.
Using logic, I again compare to recommendations on the human side of medicine when it comes to diet. Currently, for a person that is trying to lose weight or change their metabolic profile, a diet high in fruits/vegetables and restricted carbohydrates (refined carbs) is recommended. Fats are also monitored, but this will be discussed later in the article. Essentially, the human patient is encouraged away from refined or processed foods and towards a more natural, organic diet. For some, they do supplement their diet with a vitamin/mineral supplement, but for those that are serious, ideally their foods are used as their nutrient source.
Now, compare this to EMS horses and the regimen outlined above. Hays are all natural, no matter the type, but for most, the quality of that forage being fed is very low. Nutrient value is poor, protein levels are negligible, and sometimes fiber is decreased. The irony is that some of these lower quality forages are also higher in carbohydrates as compared to their more nutrient dense alternatives. Seeing is how the forage nutrient value is poor, it is then recommended to supplement with a hay or ration balancer, providing inorganic or synthetic vitamins/minerals. Then, to top it off for many, they are feeding a processed low starch grain.
While these are the general recommendations given to many EMS horse owners, they really make no sense in light of recommendations on the human side of medicine. Instead of moving towards more whole-food and natural diets in the horse, we are actually moving towards lower quality, lower nutrient dense and processed sources. Taking into consideration that the body craves nutrients not just for repair and well-being, but those whole-food nutrients have co-factors that can impact digestive health, insulin function, circulation, inflammation, and general metabolism, it just stands to reason that the current recommendations are not valid. This may explain why many horses continue to suffer the ill-effects of EMS from one year to the next, potentially with a lull in their clinical symptoms either in the summer or winter period.
The bottom line when it comes to the diet and the EMS horse? We, as a whole, need to rethink our recommendations. The diet is extremely important on many levels, but again, is just one piece of the puzzle and one contributor.
Cellular Health and Ketone Generation in the EMS Horse
In earlier discussions of this article series, I outlined two main problems that are present in these EMS horses, especially if they have ongoing laminitis.
- Inflammation/oxidative stress
- Digestive health imbalance
The increase in insulin levels in these horses is more than likely due to oxidative damage to the insulin receptor on the cell surface, which is impairing the proper utilization of insulin. As this oxidative damage continues over time without proper management, then likely the levels of insulin continue to rise on serial blood panels.
If you look at plasma levels of antioxidants and free radicals in these horses, most display what is termed ‘hyporeactivity’, implying that cellular or mitochondrial function is not at a desirable level. This was discussed in Part Two of this article series. This may be directly related to the insulin dysfunction, as insulin is needed to shuttle glucose into the cell for the creation of energy (ATP) and other substrates. If insulin is not binding properly, then the cells are not capable of functioning at the highest level. In addition, the rise in insulin leads to secondary effects in the inflammatory cascade of events, making matters worse. For me, as a veterinarian and researcher, on a cellular level I am not so much concerned about the rise in insulin or the level, but more so the implications of this rise.
The main areas of concern that I have are:
- Improper cellular energy production/function
- Improper internal/endogenous antioxidant production
In looking at human medicine, especially weight loss and cognitive health, certain diets are recommended with one being the ketogenic diet. Cells in every body must generate energy and function, and this energy can be generated through the of carbohydrates, fats, and proteins. In many insulin resistant or metabolic patients, human or equine, the carbohydrate pathway for energy production is not working properly, thus the cells suffer, as does the patient. The ketogenic diet serves one main purpose and that is to generate ketone bodies which are an alternative fuel for energy production. In addition, if the diet is followed properly, the body can be retrained to use fats as an energy source, rather than relying on carbohydrates.
The horse cannot go on a full ketogenic type of diet which is rather high in fat, however, we can make modifications to their current diets to encourage them to pursue the desired pathways metabolically. If we are successful at this, several things begin to take place:
- The body burns fat as an energy source
- Weight loss
- Increased physical energy
- Improved cellular function (free radicals/antioxidants)
Ketones or ketone bodies are produced by the liver, mainly through the metabolism of specific fatty acid types, usually medium chain triglycerides. If a horse or person is on the ‘ketogenic’ regimen and consumes too high of a level of carbohydrates, especially if refined or processed, this will negate the efforts of the diet. You want or desire to retrain your horse’s body to use fats as an energy source.
The benefits of ketone bodies in the body include:
- Increased insulin-mediated glucose uptake (improved insulin function)
- Decreased blood glucose levels
- Decreased appetite
- Increased fat burn for energy
- More energy production of ATP than glucose
- Alters the ratio of NADH/NAD and recharges antioxidants
The one interesting thing is that the higher the ketone level in the blood stream, the lower the insulin level. They inhibit one another. Thus, a horse that has higher insulin levels, due to insulin resistance, will often have the lowest ketone levels. Raise those ketone levels, and more often than not, the insulin levels will decrease. Insulin is inhibitive to ketone generation!
Generating Ketones and Cellular Function in the EMS Horse
It all sounds good, right? How does one achieve this in the average metabolic horse with or without insulin resistance?
First, as in all humans undertaking the ketogenic diet, carbohydrates must be reduced. This is difficult in the average horse as they are vegetarians by nature and every blade of grass contains carbohydrates. However, not every grass is the same. For my EMS patients, I choose higher quality and nutrient dense forages including Timothy, Orchard grass, and Alfalfa. I want to flood the body with whole-food nutrients and co-factors, and in addition, these forages are often much lower in carbohydrate levels than fescues, brome, or bermuda varieties. For most EMS horses, this higher quality forage is fed at around 1.5% of BW per day, taking into consideration pasture provisions.
Second, all grains are eliminated. This means all grains, even if they are a low-starch grain or an all-natural grain with just whole oats. These grains are a significant source of carbohydrates, often with some being very readily available to the body after consumption, which can raise the blood sugar level quickly, along with insulin, and negate our purposes. If you are feeding and relying on a grain for your horse, you must ask yourself why?? Why are you feeding it? Because your horse needs it? Because you feel they deserve a snack? Why? Every gram of excess carbs, especially if in the higher glycemic index range, can negate any effects of generating ketones in the horse. Currently, we are using alfalfa pellets as our medium for delivery of supplements to the horse.
Third, currently we use a specific blend of oils to get the widest range of medium chain triglycerides to assist the horse in ketone generation. This is not one oil, but a combination of oils given in certain amounts once or twice daily to the horse. High levels of medium chain triglycerides given to the horse has been shown in research to assist the horse in generating ketones (beta-hydroxybutyrate) and also may assist with improving the digestive microbiome.
Fourth, in some horses, especially the more stubborn ones that are resistant to generating ketones in the desired levels, I will supplement them with exogenous ketones (ketone salts) in the form of a supplement twice daily. This will often increase the blood ketone levels by 0.5-1.0 mmol, which can be significant.
In regards to other supplements in the EMS horse, I use nothing but Cur-OST herbal formulas as there are no additives, preservatives, or sweeteners. Many inorganic or synthetic supplements, including ration balancers have sweeteners of some form added to them, often listed as ‘all-natural’ flavoring. If you monitor these horses blood glucose and ketones before and after their meal with supplementation, many times there is a significant rise in blood sugar levels, despite not receiving any grain. This is likely due to the sweeteners or flavorings added to the supplements. This will negate effects of the ketogenic diet, as it is influencing glucose levels and thus insulin.
For many horses with borderline insulin resistance and current metabolic problems, the alterations to the diet and implementation of specific oils can help them to increase their ketones levels to around 0.5 mmol or higher. There are some horses that are apparently less ‘damaged’ on a cellular level than others, which respond very nicely with ketone generation at 1.0-1.3 mmol. Others are more stubborn, due to damaged mitochondria and cellular pathways, and do require further assistance.
On repeat evaluations of antioxidant and free radical loads, using plasma, a high percentage of these EMS patients demonstrate significant improvement in internal antioxidant production and also a more normal free radical level load. This signifies a return in cellular function, which is a good thing and a sign of progress. Some horses, as a result, demonstrate reduced insulin levels additionally. All positive!
However, dependent on the cellular damage level that is present, you will run into some stubborn cases. No one shoe fits every horse! This is noted as well in humans pursuing a ketogenic diet. Some just generate ketones better than others and note the benefits.
In those ‘difficult’ or stubborn horses, we are using a blend of specific antioxidants to improve cellular mitochondrial function. There are actually two blends we are using right now, not generally together, but evaluating in patients separately, with each showing promise in regards to improving cellular function. In one formula, we are using herbal extracts, while in the other, more concentrated forms of specific antioxidants. In both cases, cell function is markedly improved on repeat plasma evaluation, even after just a few days. These additional ‘antioxidant’ formulas can assist us in helping that horse to improve cellular function and likewise, ketone generation by the body. Improved cell function equates to a higher level of ketone generation.
The Equine Metabolic Patient – Summing it all Up!
Equine metabolic syndrome is complex, but it is a lifestyle driven event. Everything you choose to do can either positively or negatively impact your horse. Most regimens are implemented out of peer pressure or generalized recommendations, and more often than not, do not benefit the horse other than keeping them in the same status year after year.
In order to help the EMS horse to actually improve, their lifestyle must be changed. Additionally, you must remember that cells in your horse are not functioning correctly, so this very important factor must be addressed additionally. The ‘ketogenic’ approach in the horse has much to offer on a health level and can dramatically improve insulin and overall cellular function. This has been well known and documented in the human world of medicine and research.
Digestive health plays a vital role in EMS and laminitis, however it is not known whether if it is primary or secondary. Through our investigations, using the methods outlined above, it is interesting to note that many EMS horses (>90%) actually demonstrate a normal fecal culture after 4 weeks. This is achieved through dietary modification, the impact of ketones on the digestive tract, and implementation of specific herbal antioxidants.
The big thing to keep in mind here is that no two horses are alike. Thus, one regimen may work for one horse, while for another, the regimen may become more complex at least for the short-term. In our program, we monitor these EMS horses with fecal cultures and plasma assays for generalized cellular function. The results obtained can help guide us to determine if further steps are needed to impact the horse positively to reach our goals.
In part 4 of this article series, I will outline specific products that we are using as a baseline approach as well as other supportive measures used in the more stubborn EMS horse.
Author: Tom Schell, D.V.M, CVCH, CHN