WATCH: The 2025 National Equine Forum invited The University of Edinburgh’s Professor Bruce McGorum to discuss his recent finding, that Equine Grass Sickness is likely caused by a neurotoxic enzyme with similarities to the damage seen in snake bite victims. This toxin causes characteristic damage to the connection between nerves and muscles (the neuromuscular junction; NMJ).

Whilst there is no suggestion that EGS is caused by snake bites, the finding does raise the possibility that novel treatments for treatment of envenomation in humans could also be used to aid the recovery of horses with EGS.

You can watch Professor McGorum’s talk here: https://youtu.be/9GvIObETVng?feature=shared

This finding supports our ‘wide net’ approach to pinpointing the causal agent, as the toxin could be produced by ingested microbes, perhaps from the pasture, or within the horse by gastrointestinal microbes, in a perfect storm of environmental and horse related risk factors.

The EGS Biobank is actively seeking donations of samples from EGS cases, as well as case reports. Together these provide the vital pieces of the jigsaw for researchers to piece together all the clues.

Vets can request free sample packs from the EGSF office: info@grasssickness.org.uk

We can also provide a flat fee to help cover the cost of collecting tissues post mortem.

EGS Biobank: https://www.grasssickness.org.uk/biobank/

Report a Case: http://grasssickness.org.uk/casereports

The EGS Biobank is generously supported by The British Horse Society