Managing Obesity and EMS

Equine obesity now affects almost 50% of pleasure horses, ponies and donkeys. In man, the term ‘metabolic syndrome’ has been used to describe a collection of risk factors associated with the development of cardiovascular disease and type 2 diabetes mellitus. Defining this human syndrome was intended to improve public health by promoting recognition of, and screening for, these risk factors which include obesity, insulin resistance and dyslipidaemia. The term equine metabolic syndrome (EMS), as defined by ACVIM consensus in 2010, should also promote the awareness of, and encourage development of prevention and treatment strategies for, a commonly occurring set of risk factors which predispose Equidae to endocrinopathic (pasture-associated) laminitis. These risk factors include obesity, whether generalised (all-over) obesity or regional adiposity (e.g. cresty neck, pendulous prepuce/udder, tail-head bulge) and insulin resistance (IR). Whether ‘insulin resistance syndrome’, as once proposed, would be a more suitable term for horses and humans, has been much debated as the major underlying feature appears to be IR. However, not all outwardly obese animals are insulin resistant and neither are all insulin resistant animals obese. (We have yet to determine if normal-weight obesity [internal obesity] exists in Equidae.) Whether obesity and IR will eventually be determined to be independent risk factors remains to be seen but in the meanwhile both obesity and IR should be considered as risk factors for endocrinopathic laminitis. [...]