Question
Marsha is my 22-year-old Morgan mare that I trail ride. She weighs about 940 lb (430 kg) and should lose some weight for better health, as she only stands 14.1 hands. She has been diagnosed with equine metabolic disorder (EMS). She is allowed to graze for two hours in the early morning, though I am flexible with her turnout based on temperature and grass stress. She is fed 16-17 lb (7.5 kg) of soaked grass hay daily, always fed from a haynet. She also receives 1 lb (0.5 kg) of ration balancer twice daily. In addition to these basic components, she is fed supplemental salt, chromium, magnesium, ground flax seed, and joint support. What else can I do for her?
Answer
Because her weight is a chronic issue and because hay is the largest part of the diet, a forage analysis is necessary. Hay samples should be sent to a reputable lab, such as Equi-analytical. The values for sugar and calories in the hay will reveal if it is suitable for Marsha, if soaking is needed and, if so, if soaking will be sufficient to reduce the sugar to appropriate levels.
The amount of allowable sugar in the diet depends on the severity of insulin dysregulation and insulin levels. If a consistent hay supply is not possible to make a forage analysis worthwhile, then alternative sources may be necessary to provide a consistently low-sugar diet. Switching to a lower calorie hay might be wise, so hay intake doesn’t have to be restricted to achieve ideal body weight.
Does Marsha wear a grazing muzzle during pasture turnout? To really control insulin and weight loss, she may need further restrictions on the time she is allowed to graze, or she may not be able to graze at all.
Right now, Marsha is fed the ration balancer at its upper limit based on the manufacturer’s suggestion. Given her size, reducing this to 1-1.5 lb (0.5-0.7 kg) per day may be appropriate, though consultation with the manufacturer for its specific recommendation is best.
To summarize, the key factors here are to evaluate the sugar level in the hay, slow the rate of intake of both pasture and hay, and manage body weight. To manage body weight, increasing exercise may be necessary. Because you trail ride, it would be beneficial to increase the intensity of the work if possible, aiming for an increased heart rate for 30 minutes or longer. Working her multiple days each week, so long as her soundness persists, is best, and is thought to keep more severe endocrinopathies at bay.
Regarding supplements, EO-3 is preferable to flax, as it is a direct source of the long-chain omega-3 fatty acids EPA and DHA. Several research studies have shown that the omega-3s in marine-derived sources, such as EO-3, are better absorbed than land- or plant-based sources. Horses that are supplemented with EO-3 may have improved glucose clearance, which is beneficial for those with insulin dysregulation.
Nano-E is a natural-source vitamin E supplement. Due to its efficient delivery system, a process called nanodispersion, Nano-E reaches vital tissues faster than synthetic sources of vitamin E as well as other natural sources. Vitamin E is an important antioxidant, and supplementation is essential for horses that do not have regular access to pasture.
