Equine grass sickness

A guide to managing horses with equine grass sickness, which can be a debilitating and frequently fatal equine disease.

A guide to managing horses with equine grass sickness, which can be a debilitating and frequently fatal equine disease.

Equine grass sickness (EGS) is a debilitating and often fatal disease which commonly presents as impaired activity of the gut, caused by nervous system damage, which prevents food from travelling through the digestive system properly. 

Cases are common 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 1909, the true cause of EGS remains unknown. 

The disease can present as acute (sudden onset), subacute (milder clinical signs) and chronic (slow onset). 

Acute and subacute clinical signs include, but are not limited to: 

  • Absence of gut sounds 
  • Increased heart rate 
  • Gastric reflux (food out of nostrils) 
  • Colic 
  • Difficulty swallowing 

Clinical signs in chronic cases can include: 

  • Rapid otherwise unexplained weight loss 
  • Tucked up abdomen 
  • Drooping eyelids 
  • Muscle tremors.  

Contact your vet immediately if you suspect your horse is displaying signs of grass sickness.  

Fast Facts guide to Equine grass sickness

The front cover of the Fast Facts Equine grass sickness guide showing a chestnut horse grazing in a field surrounded by trees.

This Fast Facts guide includes:

  • Clinical signs of the different types of grass sickness
  • Treatment of grass sickness
  • Risk factors and prevention strategies

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How do you manage chronic equine grass sickness? 

The cause EGS is still unclear, but some horses survive with intensive nursing. Thanks to the dedicated team at the University of Edinburgh and with World Horse Welfare’s support, the following guide on the management of horses with chronic grass sickness was produced.  

Management of horses with chronic grass sickness

Management of chronic grass sickness horses

This guide focuses on:

  • The clinical signs of chronic EGS
  • Diagnosis and treatment of chronic EGS
  • Prognosis and recovery of horses with chronic EGS

Further updates on EGS research can be found in the guide below: 

Equine Grass Sickness: A research update and look to the future

This guide includes:

  • Advances in EGS treatment options
  • Current and future research projects to further determine the cause(s) and improve treatment outcomes

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