Equine metabolic syndrome
Does your pony (or horse) have an abnormally cresty neck? Is he more difficult than most to keep trim, or prone to developing laminitis or grass founder?
If this sounds like your equine companion, it may be worth considering whether he is suffering from equine metabolic syndrome (EMS). This condition most commonly affects middle-aged to older horses which are overweight or obese. Ponies and breeds evolved for tough conditions are most often affected, although any breed or age, in anybody condition, can develop EMS. Many questions remain about this emerging syndrome.
EMS results when the horse becomes "insulin resistant". Insulin is a hormone responsible for regulating the blood sugar (glucose) levels within the body, by promoting energy storage as fat, and in the liver and muscle. Horses with EMS become resistant to insulin (the glucose uptake into fat, muscle and liver become less sensitive). More insulin is produced by the pancreas in an effort to return the blood glucose levels (BGL) to normal. Eventually, even the high insulin levels can't control BGL, resulting in high insulin and high BG. This leads to the abnormal fat deposits, often seen at the crest of the neck, over the shoulder, around the tail head, or above the eyes.
EMS can lead to recurrent laminitis or founder. This is thought to be a result of the persistently high BGL. Laminitic bouts may be very mild to begin with, and the onset of signs is often insidious. Lameness due to laminitis is often the first sign that owners seek advice for.
Diagnosis of EMS is difficult. There are blood tests available that can be useful, although thorough clinical examination can often provide the best clues as to what may be going on. Cushing's Syndrome (usually caused by a tumour of the Pituitary gland, also leading to hormonal imbalance) can also cause similar signs and should be considered in suspected cases of EMS.
Although there is no specific treatment for EMS, these horses can be successfully managed if they are diagnosed early. This means carefully controlling diet and exercise. Affected horses generally require limited, or no, access to grass or pasture. Instead, aim to feed meadow-hay. Soaking for an hour in cold water will further decrease the sugar content of hay if necessary. High-sugar concentrate feeds containing grain such as oats, barley and maize should be eliminated from the diet, as should molasses. Generally, hard feed is not needed to maintain a healthy weight in these horses, but if it is necessary, stick to low GI alternatives.
As these horses often have painful feet due to laminitis, it is necessary to treat this before exercise can be increased. Once comfortable enough to do so, regularly exercising your horse will help control the progression of signs. Start quietly, and aim to build up to daily exercise in the form of walking, riding, lunging etc. Be guided by your horse's' level of comfort and body condition as to how much exercise is necessary and reassess often.
If you are concerned that your horse or pony may be suffering from EMS please do not hesitate to contact us. One of our vets will be happy to help put in place the best plan for you and your horse.