Recently you have been hearing more and more about the "Equine Metabolic Syndrome" or EMS. Horses with EMS have a disturbed metabolism due to obesity. Their hormones are out of balance, they underperform and can develop laminitis. What are the symptoms and causes of EMS and what can you do about it?

What is EMS?

In the Netherlands, about 55% of recreational horses are overweight. EMS is a combination of obesity, insulin resistance and laminitis Due to overweight, these horses often perform less well, they can have problems with giving off heat and regulating their body temperature, and they become less fertile. Benign fatty tumors can also develop in the abdomen, which can lead to severe colic. In addition, an overweight horse can become insulin resistant (IR). The horse is then less able to keep its blood sugar in balance. This can lead to laminitis. Finally, fat horses can get a disturbed fat metabolism. So there are several problems with EMS: • Disturbed sugar metabolism • Disturbed fat metabolism • Hormone imbalance • Risk of fatty tumors, reduced performance and reduced fertility

Symptoms EMS

There is no test that can indicate EMS. EMS is a combination of obesity, insulin resistance and laminitis. Therefore, the vet will measure the amount of insulin in the blood and possibly take an X-ray of the hooves to check on laminitis. The following symptoms may indicate EMS in horses:

• Overweight
• Not fertile
• Fat pads at the mane, tail base or in the udder
• Laminitis
• Insulin Resistence
• Overheating
• Crippled front legs
• Divergent growth rings on the hooves

Insulin resistance

Insulin resistance (IR) can arise from a disease (PPID / Cushing), but it is also very often caused by a horse being given too much or too energy-rich nutrition for a long time. If a horse takes in more energy over a longer period of time than it uses for daily life and work, all kinds of problems arise. Horses naturally eat throughout the day, but only small amounts of plants that contain little energy. We often feed them in larger meals, which can contain a lot of energy. Certainly for horses of sober breeds (such as Haflingers or Tinkers) that can quickly be too much of a good thing. Our grassy pastures are also much richer in energy than the steppes where the wild horse comes from. So it's not only the concentrate that is a problem!

The relationship between fat and hormones

There is a link between fat storage and hormones. This has to do with the living conditions of wild horses. In the wild, horse barrel hatch around the summer. They will then have a lot of fat stored for the winter, when there is hardly any food. When this fat is stored, in late summer and autumn, something also changes in the hormone balance. Fat and muscle cells become less sensitive to insulin. This is useful, the sugar level in the blood then remains more stable when there is little food. This reduced sensitivity to insulin (insulin resistance) disappears again in the spring, when the extra fat has been used and the horses come out of the winter lean again. Hard/Sober breeds, in particular, are very good at adapting to low-food conditions. But that does mean that problems arise if they live in a nutrient-rich environment all year round.

Accumulation of health problems

A horse that is constantly overweight has to deal with an accumulation of related problems. Fat tissue also produces hormones. Therefore, if an animal has a lot of fat tissue, relatively large amounts of hormones are released. In humans we know that these extra hormones cause high blood pressure, inflammation and arteriosclerosis. Moreover, large accumulations of fat often become (internally) infected. This leads to damage to the veins and the production of even more hormones which, for example, also cause insulin resistance. This is how more and more problems arise. The insulin resistance can lead to laminitis, a very painful and sometimes even life-threatening disease.

Is my horse overweight?

Overweight is the most important risk factor for EMS. On the internet you can find score cards (body condition score) with which you can walk past your horse to see if there is overweight. For example, look at the mane comb (is it big and hard?), The fat storage at the shoulder (is it thick and pillowy?) And the fat storage at the tail (see pads here?). A thick and hard mane comb may indicate insulin resistance. Fat pads at the shoulder and tail can indicate obesity. In a horse of healthy weight, you should be able to feel the ribs easily, but not see them very clearly. If your horse is overweight, it is very important for him to lose weight.

Is my horse at risk for EMS?

To determine if your horse is in the danger zone for EMS, it is especially important to know if your horse is not too fat. Because more than half of the Dutch recreational horses are overweight, we as horse owners are often a bit blind to this. It is also more difficult to see in some breeds, for example because they already have a naturally baroque neck or are more solid in construction. It may therefore be a good idea to ask the opinion of your vet. He or she can also do blood tests to determine if your horse is or is against insulin resistance. Your vet can also help you make a responsible weight loss plan.

Conclusion: EMS is a complex problem

EMS really is a syndrome. This means that several health problems are at play at the same time, which influence and reinforce each other. It is a serious disease that you really need to do something about. The most important thing is to prevent your horse from getting too fat and if he is, work on healthy weight loss. There is no medicine that can solve the syndrome. If you have a horse with EMS, you have to support the horse as much as possible. Support the horse by losing weight, limiting sugars and getting the hormone balance back in order with cannabinoids.   Sources: https://vdt.ugent.be/sites/default/files/art07inDutch.pdf https://www.diergeneeskunde.nl/media/filebank/63392a9533d64b009858ec58d1314ea0/overgewicht.pdf https://www.msdvetmanual.com/metabolic-disorders/equine-metabolic-syndrome/overview-of-equine-metabolic-syndrome