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The Fight Against Grass Sickness

Grass sickness is a devastating equine disease. Prevalent throughout the British Isles, it's fatal in both its acute and subacute forms and extremely distressing.

Grass Sickness caseAlong with the Equine Grass Sickness Fund and the Animal Health Trust, The British Horse Society is supporting an EGS vaccine trial was launched in March 2014. Our campaign is helping to provide valuable additional funding for the full three-year EGS vaccine trial project.

Most people with more than a passing interest in horses will have heard of grass sickness. Luckily, relatively few of them will actually come across a case, but those who do know just how devastating the disease can be.

Map of known Grass Sickness casesMany of us assume that grass sickness is a disease that only affects the east of the UK, particularly Scotland. While it's true that historically there has been a preponderance of cases in these areas, the map of cases reported to the Equine Grass Sickness Surveillance Scheme shows that grass sickness can and does occur almost anywhere - see the map of known cases on the left. 

Not only does the disease occur all over Britain, it can affect any horse of any sex or breed. Donkeys are also susceptible. Cases have been seen in horses of all ages although very young foals are rarely affected.

According to the Equine Grass Sickness Fund, most cases are seen in animals between the ages of two and seven, with a peak between three and four years old. It does seem that older horses develop some sort of natural immunity to the disease, probably through exposure to the cause, but even horses in their 20s have been lost to grass sickness.

In short, at present none of our horses are truly safe from the disease.


Further Information

There are three forms of grass sickness, with the acute form being the most severe.

Please read our information about grass sickness and the different forms here.

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