Grass sickness

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    This article has been edited and approved by Karen Coumbe MRCVS, H&H’s veterinary advisor since 1991.
  • Grass sickness is an often-fatal condition that typically occurs in grazing horses. It was first recognised in Scotland in the early 1900s, yet relatively little is known about the condition.

    The United Kingdom has the highest incidence of grass sickness in the world with cases being more common in spring. Young adult horses, aged between two and seven years, appear to be at the highest risk of the condition, but it can affect horses of any age.

    Grass sickness can be acute, subacute or chronic in nature. While around half of the chronic cases may recover with careful nursing, acute cases are normally put down on welfare grounds. If acute cases are not euthanised, death often occurs within 48hrs of the onset of clinical signs.

    If you suspect your horse may be showing signs of grass sickness then a vet should be called immediately.

    Grass sickness [1,073 words]: Signs | Diagnosis | Treatment | Causes | Risk factors | Prevention

    What are the signs of grass sickness?

    Grass sickness has acute, subacute and chronic forms.