Hoof Nutrition Intelligence is a twice-a-month web segment that is designed to add to the education of footcare professionals when it comes to effectively feeding the hoof. The goal of this web-exclusive feature is to zero in on specific areas of hoof nutrition and avoid broad-based articles that simply look at the overall equine feeding situation.
Below you will find Part 2 of the latest question and answer installment that you can share with your footcare clients.
Q: Should I be concerned about laminitis when turning my overweight pony out on grass this spring?
By Eleanor Kellon, VMD
A fat pony is the pasture-child for grass-associated laminitis and spring is the peak time for this concern. It can be effectively treated, but prevented only if the laminitis mechanism is understood.
There is zero evidence to support the idea that naturally occurring spring pasture laminitis is related to fructan and hindgut fermentation. In fact, all research points to it being caused by high sugar/starch and insulin resistance. Therefore, products like antibiotics or hindgut buffering agents will not be effective.
Ponies, miniature horses, donkeys, full size horses of breeds prone to insulin resistance and pregnant mares are at risk for laminitis. There also may be a history of prior episodes of spring grass laminitis in the individual animal or relatives.
Although there is a desperate need for well-designed studies to look at this concern, a factor in addition to sugar/starch levels is the magnesium content of rapidly growing grasses. In all studied species, low magnesium status worsens insulin resistance while replacing it results in improvement.
Grasses with magnesium levels that are under 0.2% and 3% or higher potassium levels can cause magnesium-related problems. This is most likely to occur in rapidly growing grasses and is made worse by fertilizers containing potassium. If animals can’t be removed from pasture, supplement the average horse with 8-10 grams of magnesium per day. However, there is no guarantee that this will fully protect against laminitis.
Limiting grazing time is not always an effective preventative. At least in part, horses given restricted grazing time have been shown to consume grass at three times the normal grazing rate. It doesn’t take a long grazing time for susceptible equines to eat enough to cause laminitis.
The best prevention is to completely avoid access to spring grass or turn a horse out for 2-4 hour intervals while wearing a completely-sealed muzzle. Feed only hay known to have a combined sugar (ESC) and starch level of less than 10%. Have minerals analyzed and properly balanced.
For an active case, start the above measures immediately, as the key to stopping the process is eliminating the cause. If you are unsure whether hay is safe, soak it for 30 minutes before feeding.
A supplement that specifically targets only magnesium, phosphorus, copper, zinc, selenium and iodine will cover the most frequently found mineral deficiencies until a hay analysis can be obtained. Chromium is useful for hays grown on alkaline soils.
Pain control is understandably a major concern, but it’s important to realize pain can't be controlled without removing the cause. While NSAIDs like flunixin, phenylbutazone or firocoxib are reasonable for a few days, they’re not very effective for pain relief since features with other types of laminitis such as inflammation, enzyme activation, and endotoxemia don’t apply to grass-induced laminitis.
Very good results have been obtained once the correct diet and trim are in place by supporting circulation to the feet with jiaogulan, L-arginine and L-citrulline to fuel production of the vasodilator, nitric oxide.
Dr. Eleanor Kellon, a staff veterinary specialist for Uckele Health & Nutrition, has been an established authority in the field of equine nutrition for over 30 years. The owner of Equine Nutritional Solutions in Robesonia, Pa., she is a founding member and leader of the Equine Cushings and Insulin Resistance (ECIR) group, whose mission is to improve the welfare of horses with metabolic disorders via integration of research and real-life clinical experience. Prevention of laminitis is the ultimate goal.
Hoof Nutrition Intelligence is brought to you by W.F. Young Co. (Absorbine). 
Like many significant achievements, Absorbine® grew out of humble beginnings—and through the tenacity of someone willing to question the status quo. In this case, it was a young woman in late 19th-century Massachusetts: Mary Ida Young. Her husband, Wilbur Fenelon Young, was an enterprising piano deliveryman who relied on the couple’s team of horses to make deliveries throughout the Northeast. Inspired by Mary Ida and Wilbur’s vision, Absorbine® has continued to add innovative products throughout the years — products used every day by horse owners around the world. Which is why, since 1892, we’ve been The Horse World’s Most Trusted Name®.
Click here to read Part 1 of the March 15, 2018 installment: How do horses determine how and where various nutrients are used by their bodies?
Click here to read more installments of Hoof Nutrition Intelligence.