Equine Metabolic Syndrome and Obesity

Affected horses have very low energy and a decreased need for calories and their bodies are in full fat storage mode. Before confirming that a horse is overweight because of hypothyroidism proper diagnostic testing should be performed since the symptoms are vague and their severity not necessarily proportionate to the severity of the disease itself.
Levothyroxine is a drug used to treat hypothyroidism. In horses that suffer from only insulin resistance and not hypothyroidism this drug may still decrease bodyfat mass and improve insulin sensitivity when combined with a carefully monitored diet and restricted access to pasture.
Obese horses are prone to laminitis
Laminitis is another major health concern that obese horses are susceptible to. The mechanism is not yet fully understood but the prevalence of laminitis in obese horses is thought to be linked to insulin resistance. Either the cells attaching the hoof wall to the lamella are not getting enough glucose or other adipokines secreted by the adipose cells trigger the laminitis. It has also been suggested that the extra weight exceeds the strength power of the lamella and detachment occurs like a tear. Most likely all of these mechanisms are involved which makes laminitis a complex subject to study and understand.
Obese horses have a hard time losing weight
Insulin resistance and hypothyroidism usually result in weight gain and the more obese the horse the more insulin resistant they are likely to become. Its a vicious cycle and one that means it is very difficult for an obese horse with EMS to lose weight. This is why it is so important to prevent obesity in the first place and to carefully monitor your horses weight.
Find your horses body condition score
Before putting your horse on a diet to prevent diseases such as EMS or IR first establish whether your horse is in fact overweight. A body condition chart weight tape and your veterinarian are all helpful tools in determining whether your horse is a good weight. The Henneke body condition chart with ratings ranging from 1 extremely emaciated to 9 extremely fat with 5 moderate being the ideal weight for most horses is very commonly used. This chart takes into consideration where fat deposits appear on a horse. If you look only at a horses ribs he might appear skinny when in fact most of the fat cells are located on the neck and on the croup. This also doesnt take into account