Equine Metabolic Syndrome and Equine Cushing’s Disease

increased levels of circulating insulin. Insulin has many functions but one of the most significant is to promote glucose uptake by the cells. Every cell in the body needs glucose to function. With an EMS individual the loss of cell sensitivity to the action of insulin causes the body to produce more and more insulin in order to get the job done. Horses as a species seem to be able to produce a nearly endless supply of insulin thus elevated blood glucose diabetes mellitus tends not to be a feature of EMS although can occur in some horses.
A high level of insulin also reduces the utilization of fuels in fat and muscle more fat gets stored than used weight gain occurs and a vicious cycle starts. There is still no consensus as to exactly how this particular chickenandegg issue works out are some horses fat because they are EMS or is EMS triggered by excessive obesity? Not all fat horses are EMS by any means and not all EMS horses are fat. The jury is still out on this question but keeping any equine on the lean side is usually more appropriate than having them too fat.
Laminitis as a Consequence of EMS or PPID
High circulating levels of insulin have another particularly devastating effect laminitis. Initially following Dr. Chris Pollitts work in the early 2000s in which laminitis was induced by an overload of chicory root inulin a type of fructan people concentrated on the fructan content of feeds as a cause of laminitis. It has since been shown that fructanoverload laminitis mimics the laminitis resulting from any septicaemia such as occurs after a feed room breakin severe colic or placentitis. These horses not only have laminitis they are systemically very ill with high fevers often explosive diarrhoea and inappetence. However these situations are not the most frequent cause of laminitis. It is estimated that over 80 percent of laminitis cases are caused by endocrine disorders with hyperinsulinemia as the main instigator. Other causes of laminitis include some infectious diseases Potomac Horse Fever Pigeon Fever or Lyme disease for example. Contact with black walnut shavings and sweet alyssum can also cause laminitis although the mechanism is not at all well understood.
Signs of Equine Metabolic Syndrome
Equine Metabolic Syndrome can be diagnosed by blood tests described below. However there are signs that an equine may have EMS and that testing is warranted. Clinical