What is EMS or Equine Metabolic Syndrome in horses?

Equine Metabolic Syndrome (EMS) is a group of symptoms not one specific disease. The more common symptoms include obesity (i.e. BCS of >3 out of 5), abnormal fatty deposits (e.g. a cresty neck), insulin resistance, and laminitis. Specific breeds or types, for example native breeds, appear more vulnerable to it than others.  It’s important to note that not all overweight horses have EMS and EMS has also been found in horses with a healthy weight.