Equine grass sickness causes progressive, often fatal neurological damage in grazing horses. Welfare management in acute cases and recognition of survival potential guide difficult decisions.
Acute equine grass sickness presents as a welfare emergency requiring rapid assessment and decision-making. Affected horses show severe, unrelenting colic pain, inability to swallow, profuse sweating, and rapid deterioration. The pain is severe and refractory to conventional colic analgesia. The welfare implications of acute grass sickness are unambiguous — the condition causes intense suffering, and euthanasia is almost invariably the welfare-optimal decision for acute cases.
The challenge for owners and vets is accurate classification of disease form at presentation. Early acute and subacute cases may appear similar, yet subacute cases have a small survival chance with intensive nursing care. This classification challenge requires experienced clinical assessment and honest welfare discussions with owners about the likelihood of recovery versus ongoing suffering.
Chronic grass sickness cases show progressive weight loss, muscle wasting, and difficulty eating. Some survive with intensive nutritional support — high-calorie feeds, hand-feeding, and unlimited grazing access — over months of recovery. The welfare of chronic cases during the recovery period is compromised by persistent difficulties eating and maintaining body condition. Careful monitoring enables welfare-appropriate decisions when recovery plateaus or reverses.