Most of us know that exercise is good for us and our horses. But many of our horses are relatively sedentary, which gives them an increased risk of obesity, insulin resistance, laminitis and other health problems. It’s not surprising that couch-potato horses get overweight quickly because UK grass in spring and summer can supply similar calorie levels as a competition mix. With high body fat levels and a life of little exercise comes an increased risk of equine metabolic syndrome (EMS), especially in ponies. EMS is a syndrome of obesity, abnormal fat deposition, insulin resistance (or reduced insulin sensitivity, leading to high circulating levels), increased risk of laminitis and lethargy. Fat is an active body tissue, producing hormones and other substances that may contribute to EMS. Some horses and ponies are more susceptible to this condition than others, and it can occur in non-obese animals.
Insulin is a hormone secreted by the pancreas in response to an increase in blood sugar (glucose) after a meal. It is involved in the regulation of blood glucose via its uptake out of the blood into the body cells, and when insulin becomes less effective (insulin resistance or reduced sensitivity), both blood glucose and insulin levels may rise. Humans affected with this condition may develop diabetes. Horses and ponies do not appear to get diabetes, but they are at increased risk of laminitis when they develop insulin resistance.
Whilst dietary control is key in the management of horses and ponies either with, or prone to EMS or obesity, exercise should also be used as an effective therapy. Exercise increases insulin sensitivity, leading to lower circulating levels of insulin and more effective uptake of blood sugar (glucose) into the body cells. The effect lasts for several hours after a bout of exercise, and an on-going incremented exercise regime (fitness training) has even more health benefits for overweight or EMS-affected horses and ponies. Exercise increases total daily energy requirements, and if an overweight horse is fed for maintenance only and exercised, they will use up body fat to make up for the deficit in energy intake. Using exercise rather than severely restricting feed intake to cause body fat loss is healthier for the horse’s body and mind.
The exercise needs to be moderate for best effects, so turnout alone is not enough and ideally an incremental training program should be used. Always start an exercise program for your horse with walking and gradually increase the intensity (gait/speed) and/or distance as your horse gets fitter. Starting slowly is particularly important if your horse is obese and they haven’t been exercised for several months or more.