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Protecting Your Horse from EMS

Man feeding Horse

Last month we covered the fundamentals of carbohydrates and began addressing some of the carb-related complications to be aware of. This month, we’re taking an in-depth look at the top 3 biggest carb-related threats to your horse and how you can properly avoid them.

Equine Metabolic Syndrome


Specialists have grouped the main metabolic issues for horses under a single term: Equine Metabolic Syndrome or EMS. The term is used to describe horses with both a metabolic and a hormonal disorder characterized by three main features: obesity, insulin resistance (IR) and laminitis.



Who’s At Risk?


Not all horses are at the same risk of EMS, even if all the external factors remain constant (diet, breed, etc.). Researchers believe that your horse’s genes play a large role in whether or not they are pre-disposed. Owners often call pre-disposed horses “easy keepers.” These horses are incredibly efficient at utilizing calories and often require less feed to maintain their body weight than other horses. EMS more commonly affects ponies or thrifty breeds (quarter horses, etc.).




The 3 different aspects of EMS (obesity, insulin resistance and laminitis) are often connected to one another. For instance, researchers believe an obese horse has a higher risk of developing insulin resistance and laminitis.

How do you tell if your horse is actually obese or just a little bulky around the edges? Obesity (also called regional adiposity) is characterized by an accumulation of fat in certain areas, such as a cresty neck (see image below), close to the tail head, just above the eyes, behind the shoulders and in the sheath or mammary glands region. Of all these places, fat over the crest of a horse indicates a much higher risk of developing EMS.

Healthy Horse Neck vs "Cresty" Horse Neck

Insulin Resistance


It helps to think of insulin as a school hall monitor whose job is to get students out of the hall and into their classes as fast as possible. That’s what insulin does, but instead of students it’s glucose (sugar) in your blood. When a horse eats, their pancreas secrets insulin into the bloodstream. As your horse’s body breaks down their feed and absorbs glucose into their bloodstream, insulin directs that glucose where it needs to go (into muscle tissues, fat tissues, etc.).

Insulin resistance is like when that hall monitor starts to get really lazy. The insulin shows up to direct glucose into the horse’s body tissues, but the act of actually absorbing the glucose happens at a much slower rate. Because they aren’t absorbing the glucose out of their blood as quickly as they should, the glucose begins building up in the horse’s bloodstream.

To deal with the higher amounts of glucose in their bloodstream, a horse’s body will start secreting even more insulin. This means horses and ponies with EMS have a higher concentration of insulin in their blood, which can be measured to determine if insulin resistance is present.




Laminitis is a painful and debilitating disease of the digital laminae (the tissue inter-connection between the coffin bone and hoof wall). One of the main issues with laminitis is that by the time clinical signs are recognizable, crippling body changes such as sinking and rotation of the coffin bone have already occurred. The problem is that diagnosing laminitis can be incredibly difficult as its symptoms mimic those of other complications. Acute laminitis may be mistaken for colic or tying up. Lameness due to laminitis may be misdiagnosed as hock lameness, bruised sole, and abscess. If in doubt, assume your horse has laminitis until proven otherwise.

Risk factors for developing laminitis include: carbohydrate overload, colic, diarrhea, excessive concussion, retained placenta, drug reactions, systemic infection, injury, obesity, genetics, and insulin resistance. While these might seem like a lot of complications to prevent, controlling the risk factors to avoid laminitis is much easier than treating the disease if it develops.


Management Tips


In the long run, it’s much easier to use proper management strategies to avoid EMS rather than treating it. The first trick is to correctly and constantly monitor your horse or pony to ensure they never become obese. This can be more difficult to spot at early stages than one might think. By the time obesity becomes obviously noticeable, often a number of detrimental hormonal and metabolic changes have already occurred. It’s imperative to maintain your horse at an optimal body condition score of 5 or 6 (1 to 9 scale).

Properly managing your horse’s diet is also key to avoiding EMS. Most pastures today are much more plentiful sources of food than earlier horses would have had at their disposal. This means their bodies’ haven’t evolved to account for such an excess of feed available. Essentially it’s like dropping a human in a room full of cake and ice cream, we just can’t help ourselves. To combat this, some nutritional experts suggest using grazing muzzles. Another idea is to alternate between pasture turnout and dry-lot turnout.

When feeding your horses or ponies for performance, choose forages low in sugars and starches. For example, Alfalfa is typically lower in sugar and starch than grass hays. Another key is to maintain a healthy exercise routine for your horse. Research has shown that exercise affects insulin sensitivity via several metabolic pathways. This makes it an important element in treating and preventing EMS.

For more ways and information on how to properly protect your horse from carb-related diseases, click the button below!

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