HORSE OWNERS and vets are being urged to submit samples from Equine Grass Sickness cases in order to help with research into a disease which is ‘virtually a death sentence’ for horses.

EGS is a devastating disease which can destroy the nerves supplying the gut, leading to gut paralysis – which has a fatality rate of 80% in affected animals.

Although it has been recognised for over a century, the causes of the disease remain elusive and there are no treatments or vaccines currently available.

Earlier this year, as a result of Moredun’s Centenary Fellowship Project, an EGS fellowship was established and now has a dedicated researcher, Dr Kathy Geyer, whose first job was to set up a national biobank of samples from EGS cases and co-grazing controls. The biobank is now home to over 1000 biological and environmental samples from horses UK-wide.

Principal research scientist Dr Beth Wells commented: “The success of the biobank project in its first season has been remarkable, thanks to the hard work of the EGS team, partner organisations, volunteers and the growing network of equine vets and horse owners, who support the biobank by sending samples in and raising awareness of the project.

Dr Wells believes the key to this disease lies within these biobank samples, however, said that progress has been hindered due to a lack of suitable samples.

“This is a hard thing to do as it isn’t always an easy conversation to have with an owner after their horse has just been euthanised. We are looking at getting donor cards set up which will avoid vets having to ask difficult questions at these emotional times.”

She said that it has also been difficult to establish a more accurate picture of the prevalence of EGS, as a lot of horse owners don’t report cases. There were just over 200 cases reported in Scotland in the last year which she said is merely the tip of the iceberg.

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Commenting on the disease itself, she said it can be linked to a number of factors, both environmental and specific to individual horses: “We believe there is a link with soil moisture and possibly underlying geology, as well as something in horses themselves. We often see EGS in younger horses which could be an indication of an immature immune system.”

In a questionnaire that was sent out to horse owners last year, she said that in two thirds of cases of EGS recorded, soil disturbance was a factor, whether that was harrowing a field and leaving horses to graze or as a result of digging. Although, she said that one mitigating factor was where digging took place to drain soil.

“When soil moisture decreases, you get less cases of EGS,” Dr Wells continued. “We are looking for some form of soil pathogen or pathogen that produces a toxin under certain conditions whether anaerobic or associated with high water content.”

She told The SF that EGS was more prevalent in horses that have 24-hour access to pasture and recommended that, in times where horse owners may be concerned about EGS, additional forage be given to horses at grass or part stable them, to reduce their time at pasture.