Equine Metabolic Syndrome in Horses: Cause, Symptoms and Treatment

Chubby horses have become a typical sight in our stables and pastures. It is not uncommon for overweight to affect robust breeds, ponies, small horses and cold-blooded horses. Too much weight on the ribs of our domestic horses is a serious matter, because the fat pads put a massive strain on the organism. The consequence can be a metabolic disease. We are talking about the Equine Metabolic Syndromein short EMS. EMS is a clinical syndrome that is associated with a complex of symptoms and in the worst of all cases results in laminitis.

Equine Metabolic Syndrome (EMS) - What is EMS?

The metabolic disorder EMS is not known in wild horses. The Equine Metabolic Syndrome is a disease of affluencethat deliberately affects our domestic horses. Unlike their wild relatives, they do not have to roam through barren areas to find enough grass. Our horses usually go to pastures and paddocks where the food supply exceeds their needs. They then return to their stables and are often given a scoop of muesli or oats. Every now and then they are allowed to "work" a little, although the word "work" is an exaggerated term for many leisure horses.

The overabundance of feed in combination with too little exercise leads over time to overweight and prominent fat pads on the mane ridge, above the eye and along the back. Apart from the fact that the high weight has a negative effect on joints and bones, the fat pads can throw the organism as a whole out of balance. Gradually, a symptom complex develops that, in the worst case, results in type II diabetes and laminitis.

The tricky thing about EMS is a vicious circle that forces the horse further and further into its health problems. The only way to break this cycle is to re-balance posture, feeding and exercise. More on this later. Let's first clarify how exactly EMS in horses develops.

Equine Metabolic Syndrome (EMS) in Horses: Causes

In healthy horses, the glucose level in the blood rises after feeding, but is quickly lowered again to a healthy level by the pancreatic hormone insulin. If the blood glucose level falls below a certain value, insulin's counterpart glucagon comes into play and raises it again.

With EMS horses however, this sugar metabolism is disturbed. The horses consume large amounts of feed, which means that the glucose level rises whereupon insulin is released is released. Insulin is responsible for transporting the glucose molecules from the blood into the body cells, where they are made available to the body as energy. However, if the horse is not sufficiently exercised and worked, this energy is not needed and is therefore stored as a fat reserve. 

By nature, horses are designed to absorb carbohydrates slowly, so normally there are no noticeable peaks in blood glucose levels. Although horses can tolerate one of these peaks well now and then, an overabundance of palatable feed will result in a permanently high level of blood glucose. Insulin production is constantly cranked up until the hormone becomes ineffective - an insulin resistance and the metabolism gets out of whack.

At the same time, the fat pads are not just fat: The fat pads typical for EMS horses also release hormones along the topline also secrete hormones involved in inflammation, including stimulating the release of cortisol in the adrenal cortex. Cortisol in turn inhibits insulin, blood glucose levels rise even further, and even more ineffective insulin is secreted - creating a vicious cycle.

The inflammatory substances in the body increase increase with the increase of fat cells and the toxic messenger substances in the circulation kill the healthy body cells, whereby the immune defense decreases. Likewise, the flood of toxins damages the liver, which can no longer adequately perform its task as a detoxification organ, so that the crown of the insidious process is feeding- or hormonal-induced laminitis is.

Because EMS is a insidious disease it is often recognized late. Also, the symptoms can be very similar to those of Cushing's. The danger of making an incomplete or incorrect diagnosis in EMS horses is very present. This is because, due to the already high levels of inflammation and stimulation of cortisol, treatment with cortisone, for example, would be fatal as it further promotes insulin resistance. The veterinarian must therefore look closely at the cause of a fat horse to make sure that it really is the Equine Metabolic Syndrome is involved.

‍EMS Symptoms in Horses: How to Recognize Them

The wobbling back and forth fat neck and further fat pads along the back up to the base of the tail are not only a typical symptom of EMS in horses., the fat and excess weight are also the trigger of the metabolic disease. A horse with EMS has a body condition score of 7 on a scale of 1 to 9.Then the horse carries a clear groove above the spinous processes, the ribs are no longer palpable under the layer of fat, also a second udder of fat is formed in mares, in geldings and stallions the tube is also enlarged by. Besides fat pads, there are other external and behavioral changes and Symptoms in horses with EMS:

• ravenous hunger, the horse is permanently hungry
• Fat pad over eye, on mane crest, neck, chest and shoulder, tube, udder, root of tail.
• Muscle loss
• Power drop
• Stiff movement, similar to cross-impaction
• Circulation problems
• Dull coat
• Rapid, heavy sweating
• Frequent drinking (polydipsia) and urination (polyuria)
• Heavy sweating
• Increasing risk of infection
• Creeping Laminitis, proceeds in spurts
• Fecal Water
• Diabetes type 2
• Fertility disorder in mares
• Lipomas (fatty growths in the abdomen), which carry the risk of severe colic

If the horse's excess weight is not tackled, the result is EMS in laminitis. So if the signs of EMS are not recognized in time to counteract them, the scenario can end in a super-GAU.

The vicious circle of the disease can be triggered by leptin resistance can be promoted even further. Leptin is considered a natural appetite suppressant and is one of the most important fatty acids in the horse, which is released by the fat pads. We all know it, the horse looks so sweet, then there's an apple here, a banana there, a treat there and so on. But beware! However, if the horse is presented with an oversupply of appetizing things, it will eventually become resistant to leptin and develop into a glutton. Hunger attacks then characterize the horse's behaviour.

‍EMS and Cushing's - What are the Differences?

A correct diagnosis of EMS is therefore of utmost importance for the long-term health of the horse. However, EMS can be difficult to distinguish from the hormonal disorder Cushing's Syndrome (PPID), especially in the early stages. Many of the symptoms overlap, making diagnosis difficult. Nevertheless, EMS and Cushing's can be clearly distinguished from each other by a few points:

How is EMS Diagnosed in Horses?

Especially in its early stages, EMS can easily be confused with Cushing's syndrome (PPID). Also, symptoms such as loss of performance, muscle wasting or a weakened immune system indicate an infectious disease, viral or other metabolic disease. Therefore, in addition to the clinical examination of the symptoms the diagnosis via the blood count must take place. In order to find out whether the horse is suffering from EMS, the insulin levels in the blood and blood lipid levels are under the microscope. For this purpose there are on the one hand the Fasting insulin and fasting glucose determinationThe test is performed on an empty stomach for at least six hours. This is because the values are most meaningful then and are not influenced by the nutrient content of the food.

To determine a truly definite diagnosis of EMS rather than Cushing's, the test is repeated within three weeks, as a one-time test could be confounded by performance, stress, season, or other illnesses.

On the other hand, there is the somewhat combined glucose-insulin test (cGIT), which is more complex, and and furthermore the oral glucose tolerance test (OGT).. In the latter, the horse is sobered up overnight and is given sugar water via a nasal tube the next morning. After just two hours, insulin levels are measured. In a healthy horse, the insulin value is below 68 mU/I insulin. In order to avoid a false diagnosis and consequently the wrong therapy, the ACTH value is also measured in older horses to rule out Cushing's disease.

‍The Treatment of EMS in Horses

If equine metabolic syndrome (EMS) has been diagnosed, there is still something that can be done about it. Because EMS is treatable. However, anyone hoping for a miracle cure is wrong. EMS horses can not be treated with medication against their pathogenic overweight. The only way out of the EMS vicious circle is to lose weight early on: With an adapted feed and exercise, exercise, exercise. A well-thought-out training plan or weight loss plan can also help with EMS to keep track of progress. Even though exercise is a super important factor in the weight loss process, the regeneration process of the horse with EMS must be taken into account. Because if you want to lose a few pounds yourself and go from 0 to 100 overnight, you can expect pain, if not injury, in at least a week.

Lose Weight Properly: Training Plans for EMS Horses

If a horse already has EMS, it is important to clarify whether laminitis or other illnesses that negatively affect the horse's musculoskeletal system have also occurred. Then the training goal should be discussed with the vet, is it realistic to pursue the goal or does the vet advise you to start with small steps first?
Basically, it can be said that a good training plan for losing weight with EMS must be individually adapted to the needs and attitude of the horse. If the horse is kept in an open stable where there is enough stimulation for the horse to move independently, the training sessions can vary in contrast to a horse that is only stabled and is put in the paddock or horse walker for a few hours a day.

In general, however, horses in open stables can also develop EMS and, just like horses from other types of housing, must have a good training plan to get EMS under control. So how do you train horses with EMS? Endurance and conditioning training are proving to be an important key to weight loss in horses and even us humans. Start taking your horse for a walk or ride through hilly or uneven terrain, this not only improves the condition and endurance of the EMS horse, but also the coordination. But be careful! You shouldn't plan a trail ride lasting several hours overnight, but perhaps start with a short round around the yard and then extend it every week.
You can find out how to create a good training plan here.

Feeding EMS Horses Correctly: What You Should Bear in Mind

Even the best training plan for horses with EMS cannot do without an adapted diet. An absolute zero diet must be avoided at all costs! Instead, the horse receives Low-energy roughagepreferably cut late and 2/3 hay and 1/3 straw. More straw should be avoided due to the risk of constipation colic. For EMS horses for basic maintenance 1 % hay per body weight is completely sufficient. A small horse with a body weight of 480 kg should therefore receive around 4.8 kg of hay - no less! not less! The hay can also be soaked for at least 30 minutes. Concentrated feed Horses with EMS and overweight generally do not need concentrated feed.

Which Mineral Feed Do You Feed an EMS Horse?

A complete mineral feed with a low sugar and starch content is important when slimming down in order to compensate for the missing nutrients from any roughage that may have been washed out. In particular, the manganese value should be examined. It is not uncommon for manganese deficiency in EMS horses. can be prevalent. Manganese is an important player in sugar metabolism and is closely linked to the hormone glucagon. If there is a manganese deficiency, this can lead to undesirable food cravings because the blood sugar level is no longer raised after it has been lowered by insulin.

You Should Avoid These Foods if Your Horse Has EMS

The following feeds are taboo for EMS horses.: Sweets, such as apples, bananas and bread, which only raise blood sugar levels unnecessarily. Haylage, grass silage, flavorings, preservatives and sweeteners are also a No-go for EMS horses. These go on the liver and stress it so that the toxins released in the weight loss process cannot be filtered out. A damaged liver also means laminitis again.

Horses with EMS should be supported in their diet for the sake of their liver by herbs such as milk thistle, birch leaves, nettle and dandelion.

And as sorry as it is, the lush, green pasture is also canceled for EMS horses. As an emergency solution, it may be possible to resort to a muzzle, with which the horse can still experience the time in the pasture with his pals.

‍Move, Move, Move - Training Plan for EMS Horses

Exercise improves insulin sensitivity, because the sugar in the blood is immediately reinstated by exercise and not stored in the first place. And that saves insulin. Just 20 minutes of walking can significantly improve insulin sensitivity. Furthermore does EMS-horses benefit from exercise because fat burning is increased and muscle mass is built up. The cardiovascular system is also strengthened.

Pay attention when training an EMS horse be careful not to overdo it right from the start. Increase the workload step by step in the true sense of the word. Because training in the anaerobic range, which leads to muscle overacidification, can again have too strong an effect on the detoxification organs and thus further stress the already weakening metabolism.

How intensively a horse with EMS needs to be moved and trained depends, among other things, on its eventual hoof reloading. If the thrust has subsided and the horse has a stable hoof situation, it can be exercised on at least four days a week without or with light rider weight. 30 minutes of brisk trot and quiet canter are appropriate.

Has the EMS horse however, does not have laminitis, it can also be worked up to six days a week with and without a rider. Here, at least 30 minutes of work with a lot of concentration power, forehand and hindquarters activation and canter units are planned.

Both the diet plan and the training plan should always be done in close consultation with the attending veterinarian.

Frequently Asked Questions About EMS in Horses

Can my horse inherit EMS?

On the one hand, the reasons for metabolic disease are an over-supply of good feed and a lack of exercise, which ends in pathogenic overweight of the horse. On the other hand, researchers previously assumed a heritable probability of EMS of around 40%. However, recent US studies have found that the genetic predisposition is much higher than previously thought, at 80%. The reasons why a horse is more likely to develop EMS than other horses of similar weight and fat percentage may be rooted in its genetic makeup. Researchers hope to use these findings to develop a genetic test to determine whether or not the parents have a genetic predisposition to the metabolic disease.

Can Equine Metabolic Syndrome (EMS) in horses be cured?

Once EMS is recognized in the horse, there is a good chance of cure. However, there is no panacea for EMS on the market - horse and owner must choose the long, arduous path of exercise and feed rationing. However, if you think your EMS horse will get enough exercise in a loose stall, you are wrong. In the case of EMS, the pounds will only fall off with a targeted exercise plan. So before it comes to the super disaster laminitis, horse and owner have the best chance of recovery with a diet. Therefore, it is important to always keep an eye on the horse's weight to prevent overweight from occurring in the first place.

‍Should I feed my horse chromium for EMS?

In connection with EMS-horses, it is often claimed that chromium yeast helps to reduce weight and improve insulin sensitivity. However, according to current knowledge, it has no effect whatsoever on making the pounds fall off more quickly or on bringing the horse's sugar metabolism back into balance. On the contrary, chromium may even be carcinogenic. Especially since chromium is present in sufficient quantities in the plants that our horses eat. Therefore, a chromium deficiency does not usually exist in horses. It is better to stay away from chromium in EMS-horses and instead concentrate on a sufficient amount of exercise.

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