The Body Condition Score (BCS) is a great way to get an idea of your horse's weight compared to an average.  There are a couple of scales that can be used, which range from 1 through 5 or 1 through 9.  We tend to use a scale of 1 (poor/emaciated) through 9 (extremely obese) as it's a bit more informative.  

The ideal BSC for a horse is about 5/9.  However, you do have to keep in mind what your horse's body type is as well as the type of work that he'she does.  For instance, a fit thoroughbred racehorse is often a 4/9, while a pleasure horse or draft can be healthy at a 6/9. 

So how do we determine where a horse falls on this scale?  Well, we take a look and feel at certain areas of the body to determine fat deposits.  Those areas include the crest of the neck (A), the withers (B), the crease along the back (C), tailhead (D) and over the ribs (E & F).  By inspecting these areas, one can easily assign a score to your horse.

If you would like to understand more about what the numbers mean, check out Purina's Body Condition Scoring Chart.  

While one of the most common  metabolic disorders in horses is Cushing's disease, a close second is Equine Metabolic Syndrome (EMS).  EMS can first be noticed in young to middle aged horses who have a predisposition to gaining weight.  So called "easy-keepers" often don't need much feed to maintain a healthy BCS. 

One of the hallmarks of EMS is regional fat deposits.  We often see horses with large, cresty necks and fatty areas over the hindquarters ("That sweet feed is going to go straight to my hips!")  These horses are often rated at >7 on the BCS scale, but not all horses with EMS are overweight.  They can appear thin over the ribs, but have tail head and neck deposits indicative of the disorder.  Certain breeds such as ponies, Morgans, Quarter horses, and Tennessee Walkers may have a genetic predisposition to this syndrome.     

Another characterization of this disorder is Insulin Resistance, which we will delve into in the next section! (Isn't the anticipation killing you?!)

Rotated P3 in Laminitis

One of the major concerns with overweight horses is laminitis.  The increase in weight puts more stress on their feet, which can predispose them to this devastating disease.  In addition, EMS horses have an increase in circulating cortisol, a stress hormone.  This further increases the risk of laminitis in these animals.  These horses commonly have subclinical laminitis (meaning you don't really know anything is wrong) and then they become acutely footsore.  That is why it's important to recognize EMS early. 

Oftentimes, clinical signs are enough to make a diagnosis and their lifestyles can be adjusted for the issues at hand.  To be sure, there are a few tests that we can perform.   We can generally get a good idea of a horse's EMS status by testing 3 things - Glucose, Insulin, and Leptin.  Glucose and insulin are pretty straight-forward.  They work the same as in a diabetic human. (Note: EMS is not diabetes, but has some similarities.)  Fasted insulin levels in these horses are often above normal.  The third test is for Leptin.  Leptin is secreted by fat tissue and is a great marker for EMS.  If leptin levels are elevated, we're pretty sure of our EMS diagnosis. 

There are other tests that can be performed, such as a Glucose Tolerance Test, however these tend to be a bit riskier and we have had good results from just looking at the three molecules listed above. 

There is generally some confusion about insulin resistance. Insulin resistance (IR) is not a true disease.  Rather it is a symptom of other diseases, such as Equine Metabolic Syndrome.  There is a high correlation between obesity and IR, as well, which is outlined well in this article.  In this instance, obesity is the cause of IR.  

Insulin resistance occurs when there is a failure of tissues to respond to the effects of circulating insulin.  This is often an affect of rising cortisol levels.  As the body continues to produce more insulin, glucose levels begin to rise accordingly and the body's ability to process soluble carbohydrates decreases. 

That is a pretty basic overview.  There are a couple of different ways that IR can develop, and obviously there is a lot more going on that just those two sentences.  It's fairly complicated disorder, but can be managed through some basic changes. 

There is a difference between obese horses and horses with EMS.  So we'll break this section down a bit to talk about them separately.  However, some of the same goals need to be attained.  

As in most species, obesity in horses can be multifactorial.  The most common reasons are overfeeding and lack of exercise.  Believe it or not, horses don't always need grain! <GASP!>.  I know it's shocking, but horses survived for centuries without it.  There is often a feeling of sympathy if a horse does not receive a grain meal, so we feel obligated to give them a scoop of something.  What are your horse's requirements for the work that he's doing?  Does your horse need a scoop of sweet feed twice a day?  (As an addendum, check out our blog post "What's the Scoop?") 

For easy keeping, pasture-potato horses, good quality hay and a ration balancer is all they usually need.  Some horses in light work do fine on this diet as well.  Easy keepers that are kept on excellent pasture can easily fatten up, however, so their turnout time either needs to be limited or you may need to apply a grazing muzzle for all or part of the day.  Appropriate grazing muzzles should allow some grass to get through, but only small amounts at a time.  Hay nets can also decrease the amount of feed intake per day, as they have to work harder to get to it. 

The general theme you should keep in mind when feeding overweight horses is restriction of calories.  Decrease soluble carbohydrates (anything with molasses counts!) and focus on roughage/fiber. 

Now what about horses with EMS?  Well, it's actually pretty similar.  The biggest issue with EMS horses is that you have to severely limit all Non-Structural Carbohydrates from their diet.  That means that anything with sugar added (treats, sweet feed, chopped forage, spring pasture) needs to be eliminated.  Instead of good quality hay, we generally recommend lower quality hay and then feeding a calorie restricted grain, such as Nutrena's SafeChoice Special Care.  If more calories are needed to maintain body weight, we begin to focus on obtaining energy through fats instead of carbs.  Fats are actually a safer source of calories to feed horses with EMS, causing much less of an increase in insulin than carbohydrates.