Equine Grass Sickness Fund launches fresh appeal to fund research into the disease

The Equine Grass Sickness Fund, part of the Moredun Foundation, has launched a fresh appeal for donations to fund research into equine grass sickness (EGS), a serious condition affecting the nervous system of grazing horses and ponies that remains poorly understood and has no cure. The fund recorded 74 confirmed cases by 11 September 2026, up from 67 the previous year, and researchers believe the true figure is considerably higher, since many cases are thought to go unreported.

Scientists studying the disease think it may be linked to changeable grazing conditions, such as warm days followed by cold nights, or a sudden flush of grass growth after a dry spell, though the precise biological trigger is still unknown. To help find answers, the fund has built a biobank of tissue samples, supported by the British Horse Society, and grows lab-based models of equine organs to study how the disease develops — research that depends entirely on charitable donations to continue.

For owners and breeders, the charity's advice is to introduce any changes to grazing or diet gradually, stay alert to the weather conditions associated with higher risk, and report suspected cases so researchers can build a clearer national picture of when and where EGS occurs. The fund also runs a free alert service to flag higher-risk conditions by area.