As a past Scottish Championship dressage winner, Gillian Green had years of experience of being around horses.

But little prepared her for seeing her own horse struck down by equine grass sickness, a baffling  disease which kills around one in 200 horses in the UK every year. 

Having nursed Jed back from the brink, Gillian and her sister, Emily Anderson, are now playing their part in trying to solve the 120-year-old riddle of what causes the dreadful illness to strike.

Gillian, who is manager of the National Soils Archive at the James Hutton Institute, said the first sign something was wrong was when her otherwise healthy seven-year-old, 18.3 hands high warmblood horse choked on his hay net while eating.

“I thought he was just being greedy,” she told the Institute's recent Hutton Highlights podcase. "He seemed fine, so he was ridden that day.

“The next day he choked again and right before my eyes he started to shake from head to foot and sweat so badly you could catch the fluid in a bucket underneath his tummy.

“He was obviously distressed, and his heart rate was high which is a pain indicator. So immediately the vet was called.”

But Jed’s ‘hyped’ state was not a typical sign of equine grass sickness. Instead, it was suspected that he might be suffering from a tumour on his adrenal glands.

After three days however, his behaviour changed. “He adopted a typical grass sickness stance which looks like an elephant standing on a bucket with their four feet cramped together and his back hunched,” said Gillian. “His eyelids started to turn down.”

With chronic grass sickness confirmed, the sisters worked around the clock trying to coax him back from the brink. 

Emily offered bucket feeds every hour during the day, and Gillian spent a month sleeping in her car and getting up every hour through the night to try to tempt Jed with everything from broccoli to tomatoes.

“It was very emotional,” she added. “You have to encourage the horse to eat when they don’t want to and some of them physically can’t. He was one of the lucky ones that could still swallow and digest some food.”

In her role at the National Soils Archive, Gillian is responsible for processing soil samples taken from equine grass sickness locations for storage and future analysis.

They will be used alongside biological samples taken from horses which are held by the Equine Grass Sickness Biobank, a three-year project which aims to finally unravel the mysteries of the disease.

Meanwhile Emily, who has six horses at the same stables as Jed, has donated £4000 towards processing the samples - raising funds to keep the project going is crucial in the search for answers.

Emily said: “It was a very harrowing experience. Horses with the chronic version can suffer depression - Jed became very depressed.

“We are very lucky that he was one of the very few survivors, but we have had friends who have tried just as hard as us and loved their horses just as much and they don’t survive. That is one of the evilness about it, you can try your very best and you can’t do anything about it.”

To support the project, visit www.hutton.ac.uk/research/support-equine-grass-sickness-research