The Guernsey States vet has confirmed that equine grass sickness (EGS) has been found on the island.

The predominantly fatal disease, which affects grazing horses, ponies, and donkeys, causes abdominal pain, a distended intestine, and an increased heart rate. There is currently no vaccine or treatment. The Animal Health Trust confirmed a privately-owned horse died from the disease.

States Vet David Chamberlain called EGS "devastating", and said the cause was a mystery. He said he believed the unusual weather and rapid grass growth may have been a factor. Horse owners have been advised to remove their animals from the affected field, he added.

The States Vet would not confirm exactly where the horse died.