Question
My 17-year-old Morgan mare weighs about 1,200 lb (550 kg) and is in moderately fleshy body condition, just right by my estimation. I ride purely for pleasure, usually at the walk and trot. On days I don’t ride, I longe her. She’s fed 13-18 lb (6-8 kg) of soaked hay daily, 3 lb (1.5 kg) of unmolassed straw/alfalfa chaff, a vitamin and mineral supplement, and biotin. She maintains her weight on this. Her hooves are strong, but her coat does not shine as it should. She has equine metabolic syndrome (EMS) with bouts of mild laminitis. This year she was extremely sensitive to the grass and has spent long stretches in her stall following a laminitic episode that was more severe than usual. Despite these laminitis flares, she has no radiographic changes to her coffin bones. She’s added something new to her list of ailments lately, though: occasional mild colic. What else can I do for her from a nutritional perspective?
Answer
A diagnosis of EMS with laminitic episodes can make diet formulation a challenge, though you seem to be on the right track. Her basic ration, which consists only of forages and vitamin and mineral fortification, is appropriate given her body condition. You are wise to offset the potential soluble carbohydrate content of her hay by soaking it prior to every meal.
In reference to future grazing, however, continue to proceed cautiously and under the direction of a veterinarian that is familiar with the mare’s endocrine-related problems. She has shown that she is becoming more and more sensitive to pasture grasses, so her time spent grazing might be restricted, even severely so, in the future. Some horses with metabolic disorders cannot handle grazing at all, regardless of season, time of day, or pasture composition. For these horses, a drylot that allows them to exercise as they wish with suitable preserved forage at their disposal is an option. With respect to pasture and hay, try to keep the level of nonstructural carbohydrates below 12%.
Two high-quality supplements from Kentucky Equine Research might also help, especially if you believe she may be able to tolerate some grazing in the future, even if it’s limited by a grazing muzzle of another means of restriction. EquiShure is a time-released hindgut buffer that supports digestive health by minimizing disruptions in the microbial population brought about by diet or management changes, including those prompted by grazing. EquiShure stabilizes the pH of the hindgut and reduces the incidence of recurrent colic in some horses.
Another research-proven product recommended to reduce inflammation and support a normal endocrine response is EO-3, a marine-derived supplement that provides the specific omega-3 fatty acids DHA and EPA, which are known to have many health benefits. Further, EO-3 will likely add shine to her coat and may keep certain skin problems, such as scratches, from developing.
