Saturday, March 2, 2013

Equine Metabolic Syndrome - Treatment

Equine Metabolic Syndrome: Treatment

 Before you get on line and Google Equine Metabolic Syndrome (EMS) and Treatment be sure to take some Advil because you are likely to end up with a headache! There are many companies marketing supplements aimed at horse owners desperate to help their insulin resistant laminitic horses, and it is very easy to become confused and tap out your checking account trying to help your horse and not really accomplishing much.

Try to keep going back to basics when you think about EMS:  it is a disorder of energy metabolism.  Any effective treatment should be directly related to diet, exercise, and/or the body's energy processing mechanisms.  Here I will go down the list of things that we KNOW, based on clinical and laboratory research, can help the EMS horse.

1) DIET.  
Most horses with EMS, unless their athletic activity  specifically increases caloric needs, should eat 1 - 1.5% of body weight daily.  For a 1000 pound horse this is 10-15 pounds total daily food (this includes EVERYTHING that passes their lips).  This diet should be low in high glycemic index food stuffs.  Grains have relatively high glycemic indexes, as do some hays which are high in certain sugars. All hay fed to insulin resistant horses should be analyzed for sugar content.  Sugars are complexed into carbohydrates and starches, which are converted to sugar during the digestive process.  Because or variations in each horse's digestive environment, it is impossible to precisely predict the amount of sugar a given hay will produce in each individual horse, therefore we follow certain guidelines in choosing hay to feed insulin resistant horses. These guidelines are based on the hay's carbohydrate and starch content.

Trying to interpret hay analysis lingo can be challenging.  For an excellent review, go to
Historically, the recommendation for insulin resistant horses is to feed hay that is less than 10% non-structural carbohydrate (NSC).  

As hay analysis techniques advance, the reporting nomenclature has changed.  Instead of reporting NSC, you may find water soluble carbohydrate (WSC) and starch on your report.  Add these together to get NSC:
NSC = WSC + Starch

Most recently, WSC has been replaced with ethanol soluble carbohydrate (ESC) which measures a subset of the carbohydrates in WSC which are believed to be those with the highest risk of inducing laminitis in IR horses. If your analysis reports ESC and starch, then add these together to estimate your NSC.

Finding consistent sources of low carbohydrate hay is challenging.  The company most frequently used for analysis is Equi-Analytical.  They have a great website.  Try to establish a relationship with a hay broker, or hay grower who is willing to analyze their hay, and stick with that supplier.

2) Exercise
Regular exercise is a critical part of the management of horses with EMS.  Upcoming posts will be directed at specific conditioning recommendations for various types of sport horses.  Unless afflicted with active laminits, there is no reason your EMS horse cannot be an athlete, even if it is on a limited basis.   

3) Hoof Care
 Whether your EMS horse is laminitic or not, regular attention by an experienced farrier or qualified barefoot trimmer is essential.

4) Levothyroxine. 
Thyroid hormones are responsible for regulating your metabolic rate, or the rate at which you metabolize energy (back to basics: EMS is a defect in energy metabolism). An actual hypothyroid condition in horses has not been recognized, and in general, testing thyroid hormone levels (T3, T4) is not useful or recommended in EMS horses.  Thyroid hormone levels fluctuate throughout the day and unless a complex thyroid stimulation test is conducted in a hospital setting, it is impossible to interpret thyroid hormone levels drawn in the field.  As a result, horses are frequently misdiagnosed as "hypothyroid".

However, because insulin resistant horses do not utilize sugar normally, using thyroid supplementation to artificially increase the metabolic rate in overweight horses with EMS has been shown in a clinical research setting to be useful in improving metabolism and inducing weight loss.  Supplementing thyroid hormone is NOT specifically treating equine metabolic syndrome OR a hypothyroid condition.  It is simply helping your horse improve the utilization of energy which is disturbed by the underlying defect in metabolism inherent in EMS. Supplementation of levothyroxine is usually an intermittent treatment, based on an individual horse's body condition.  To be effective in a weight loss program, levothyroxine should be supplemented at a relatively high dose, under the direction of your veterinarian.

5) Metformin

Metformin is a human medication used to treat type 2 diabetes.  In humans, it lowers blood sugar, decreases glucose production by the liver, improves insulin sensitivity, and decreases glucose absorption from the gastrointestinal tract. Metformin activates AMP-activated protein kinase (AMPK), an enzyme that plays an important role in insulin signaling, whole body energy balance, and the metabolism of glucose and fats.

There is conflicting evidence for the efficacy of metformin in horse with EMS.  The problem is that metformin is not consistently absorbed from the gastrointestinal tract of horses, so the concentration of the drug that is reached in the bloodstream may vary significantly from horse to horse.  However, in at least one research trial, at a dose of 30 mg/kg twice a day, there was a beneficial effect on insulin levels and glucose handling in the group of horses tested.  Because metformin is affordable and has no significant negative side effects, it is widely used in laminitic horses with high insulin levels.

6) Pysillium

Feeding 4 ounces of psyillium daily may have beneficial effect on insulin regulation, based on a recent research trial at Montana State University in a group or normal horses.  Go to our HighDesertEquine Facebook page to find links to more on this topic.  This is another easy, safe addition to your EMS horse's diet that may have beneficial effects.

7) Chromium and Magnesium

Chromium and magnesium are involved in glucose and insulin regulation.  There is evidence in humans that supplementation can benefit people with type 2 diabetes.  Conflicting results with chromium supplementation exist in horses.  It is unlikely that supplementation will do harm, but cost and the quality of products must be taken into consideration.  If you decide to use a chromium/magnesium supplement in your EMS,  first be sure to buy from a reputable company,  be sure that the supplement does not contain additional carbohydrate, and ask the manufacturer for research or clinical trials conducted with their product.  If they cannot produce hard data supporting their product, don't buy it.

I believe that education is the key to evolution. I believe that animals are the key to compassion. I believe the learning never stops.

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