Insulin Resistance in Horses

Eleanor Kellon VMD staff veterinary specialist at Uckele Health and Nutrition owner of Equine Nutritional Solutions and owner and veterinary advisor for the Equine Cushings and Insulin Resistance ECIR Group Inc. This is often hard to spot because both feet are equally affected.
Signs include
Stiffness at the walk with loss of normal sidetoside sway
Stiff head carriage
The head held either higher or lower than normal when moving
Reluctance to make sharp turns
Hesitation to move off from a standstill
A preference toward soft ground
A slower shortened stride on hard footing
If you notice any of these signs talk to your vet about testing and treatment for insulin resistance. A good program should help clear up these signs of lowgrade laminitis.
Treatment Options
Successful treatment for insulin resistance lies in a foundation of diet and exercise.
Kellon recommends feeding insulin resistant horses grass hay with a combined sugar ethanolsoluble carbohydrates aka ESC plus starch content of 10 percent or less fed at 1 5 percent of current body weight or 2 percent of ideal body weight whichever is larger.
Carriers for minerals such as feedstuffs to balance the diet should be less than 10 percent sugar plus starch Kellon adds.
She recommends analyzing your horses hay for mineral content so supplementation can be customized to the hay. Some considerations should be kept in mind like a calcium to magnesium ratio no higher than 21 and iron to copper to zinc ratio of 413.
Soaked wellrinsed beet pulp is an ideal feed for IR horses. The Equine Cushings and Insulin Resistance Group Inc. maintains a list of other safe feeds.
Exercise is also very important. Turnout while better than a stall does not equate to exercise.
There are medications available for horses whose insulin resistance cant be controlled with diet and exercise alone. Usually these horses are plagued with chronic

laminitis
Metformin has the longest history of use but doesnt work for some and may lose effectiveness over time Kellon says. A group of drugs called SGLT2 inhibitors is being investigated and showing promise. Other than mineral balancing and some supplements to help with laminitis there are no effective supplements for metabolic syndrome.
Pasture grazing is risky for a horse with insulin resistance both because sugar is higher in fresh grass and because levels change significantly from day to day.
Spring and periods of rapid regrowth are particularly dangerous but nothing is guaranteed safe Kellon explains.
She suggests horse owners avoid allowing an IR
horse to graze until the horses condition is wellcontrolled and he is back to a significant exercise level. After that the horse should only be allowed to graze for 30 to 60 minutes and only immediately after exercise. Skeletal muscle is the major consumer of glucose in the horses body.
Exercise results in glucose uptake by pathways that do not require insulin thus relieving the pancreas and insulin of much of their work Kellon says. The effect is strongest for an hour or so after exercise but still present 24 hours after exercise. As the horse becomes fit the improved insulin levels and reduced insulin resistance will last for as long as a month after regular exercise is stopped. Its common to hear of IRprone horses like Arabians that had no issues with grazing or grain when in heavy work becoming obese and laminitic within a month of stopping work.
Potential Complications
Once your horse has been diagnosed its important to remain alert for possible complications. A common one is an uncontrolled appetite which if left unchecked can lead to obesity.
Horses may also become more sensitive to common allergens irritants and vaccines. Hypertension and elevated triglycerides may develop but by far the most significant complication is laminitis.
Regardless of potential problems the bottom line is that there is significant hope for the future of any horse diagnosed with insulin resistance.
Related Conditions
The Equine Cushings and Insulin Resistance ECIR Group Inc. was formed in 1999 to help share information and experiences among owners and professionals dealing with what is now known as pituitary pars intermedia dysfunction or PPID. It was formerly and still colloquially called Cushings disease.
Equine metabolic syndrome EMS insulin resistance IR and PPID often have overlapping clinical signs that can make a diagnosis difficult. The ECIR Group works to help caregivers achieve that end.
With
thousands of international members the groups discussion forum is arguably the largest field trial in the world for both PPID and EMSIR. It provides the latest research medication information and dietary recommendations for horses with these conditions.
In 2013 the ECIR Group an Arizona nonprofit corporation was approved as a 501c3 public charity. Taxdeductible contributions and grants support ongoing research education and awareness of PPID and EMSIR. The group also hosts a NO Laminitis! Conference five of which have been held since 2011.