Horse Grass Sickness: A Devastating Welfare Condition

Equine grass sickness (EGS) is a serious and often fatal neurological condition of horses and ponies, linked to grazing on affected pasture. Understanding it is vital for horse welfare.

Key Facts

Equine grass sickness affects the nervous system controlling the gut, causing gut paralysis and accumulation of ingesta
Acute and subacute forms are almost universally fatal; chronic EGS has a survival rate of around 50-75% with intensive care
The exact cause is linked to the bacterium Clostridium botulinum producing neurotoxin in the gut
EGS hotspots exist particularly in Scotland, the north of England, and parts of Scandinavia
Affected horses show sweating, muscle tremors, difficulty swallowing, nasal discharge, and gut stasis
Chronic EGS survivors require months of intensive nursing care including assisted feeding
Risk factors include young horses (2-7 years), sandy or disturbed soil, cool dry weather, and recent pasture change

Welfare Considerations

Equine grass sickness causes profound suffering. Gut paralysis means the horse cannot pass food or water normally, leading to colic pain, dehydration, and progressive muscle wasting. The decision to euthanase acutely affected horses or commit to intensive chronic case management is one of the most difficult in equine medicine. For chronic survivors, recovery is possible but involves weeks of tube feeding, nutritional support, and careful management - a testament to the bond between horse and owner when done well.

What You Can Do

Know the risk factors for grass sickness and discuss prevention strategies with your vet
Be alert to early signs including muscle tremors, difficulty swallowing, and patchy sweating
Contact your vet immediately if grass sickness is suspected - hours matter in acute cases
Support the Equine Grass Sickness Fund which researches prevention and treatment