Equine Grass Sickness

horse eatingEquine Grass Sickness (EGS) is a debilitating and frequently fatal disease of horses, ponies and donkeys, which commonly presents as impaired activity of the gut, caused by nervous system damage.


Cases occur frequently, but not exclusively, in northern European countries, particularly Great Britain. The disease occurs almost exclusively in horses with access to grass, but even though the condition was first identified around 1907, the true cause of EGS remains unknown.


Download our Equine Grass Sickness PDF for more information on the disease.


For many years World Horse Welfare sponsored horse carers working with chronic cases of grass sickness, a potentially deadly disease. The cause is still unclear but some horses survive, usually only with intensive nursing. Thanks to the dedicated team at the University of Edinburgh and with World Horse Welfare’s support, a Guide on the management of horses with chronic grass sickness is now available.