Although this syndrome has been known for decades,the importance of understanding this condition is now the focus of many horse owners. Although laminitis can be caused by stressors such as infection and retained placenta, the major complication of EMS is laminitis.
A typical presentation of EMS is an obese horse with fat occurring generally or regionally (such as in pockets on the hip or in the crest). This horse is usually Insulin Resistant (lab values),predisposed to laminitis and obese.
Dr. Ray Geor- powerpoint presentation and references
Some people use the terms peripheral Cushings and prelaminitic syndrome but the researcher Dr. Ray Geor from the University of Minnesota Veterinary School believes that EMS is the proper term. He is the presenter in the powerpoint presentation listed on this page. It is an hour lecture that reviews the causes and management of equine metabolic syndrome.
The vet may be called to see a horse because the owner realizes the horse has grazing-associated laminitis over time, an acute bout of laminitis without a known cause, retains weight with a big crest or fatty deposits on the body, or has recurrent lameness after farrier work.
Dr. Geor cites studies where laminitis is induced after 3 days of administering excess insulin to groups of horses. He also cites studies that show chronic inflammation may lower the threshold for the amount of increased insulin to induce laminitis. He acknowleges that there is much research to be done to understand and diagnose this problem. Diagnostically, blood levels of insulin and glucose can help diagnose the problem, but a clinical history of laminitis and obesity is enough to take action.
This complex metabolic problem has no easy solutions. To make a difference a horse must lose weight and consume food that will not incite increased insulin levels; and even that action may not resolve the situation. The owner must be diligent in the management of diet and exercise.
Dr. Geor suggests many horses must be off pasture for months and eat a poorer quality hay (not dusty!!) to reduce the amount of quickly absorbed carbohydrates consumed. Hay should be fed throughout the day without grain and treats. His feed example: for a 1100 pound horse the total amount of hay needed for the entire day is 13 pounds. This hay must be weighed. He figures this is 75% of the calories to maintain weight. If the hay volume and weight is reduced too much, behavior problems and gastric issues may occur. After 3 months the horse should show weight loss as measured at the girth. Interestingly, the pockets of fatty tissue, including the neck crest fat may not be reduced so quickly. Dr. Geor endorses the use of the girth weight tape because this is where the weight loss will be apparent. (be sure to use the exact same spot each time you take the measurement).
He offers other impressions:
Pasture can be deceptive. Studies have shown that after just 2 hours of pasture a horse can consume half of what he needs for the day. A grazing muzzle may work but must be monitored for behavior problems and its effectiveness in limiting intake. There is no scientifically known way to "look" at a pasture and know by the time of day or season what the sugar content may be. Trying to reduce high sugars including fructans in the feed is the goal. Manufactured feeds designed for this purpose are helpful as well as the use of non-molasses type beet pulp. The equine gut wants consistency. He suggests redesigning the diet slowly but then remaining consistent over time. Regarding the use of a lab like Equi-analytical to check hay, he indicates that due to the expense this may only be practical if you test a few sample areas before you buy a large quantity of hay. He does say that soaking hay may or may not help the problem citing a study showing marginal sugar depletion after 10 hours of soaking.
It seems poor hay,no pasture, and manufactured specialty feeds may be the only sure ways to offer your horse consistent food that does not cause the body to produce excess insulin, which could lead to laminitis in the susceptible horse.
Note: He indicates that non-obese laminitic horses do exist and need a similar approach but with more poor hay (even 24 hours a day if needed) and additional oil.
****Also, since the hay may be poor, a pound of a nutritional supplement daily may be needed for all horses
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WEB LINK for Dr. Geor's presentation. Please note the lecture starts 3 minutes into the video due to set up procedures. Be patient, it will start.
