Horses with the rare nerve condition, equine grass sickness, have similar signs of disease as people with conditions such as Alzheimer’s, a study has found.
The findings, published in the journal, Molecular and Cellular Proteomics, shed new light on the causes of the mostly fatal horse condition and could help to develop new tools for diagnosing the illness.
Scientists say that horses affected by equine grass sickness could also hold clues to human conditions.
Grass sickness attacks nerve cells in horses but the causes remain unknown. It causes gastric upset and muscle tremors, and can kill within days. If diagnosed quickly, animals can sometimes be nursed back to health.
Researchers from the University of Edinburgh’s Roslin Institute and Royal (Dick) School of Veterinary Studies looked at nerve tissue from six horses that had died from equine grass sickness in a bid to investigate the causes.
They found that the horse tissue contained proteins commonly seen in the brains of people with Alzheimer’s disease, such as a build-up of amyloid protein.
In total, 506 different proteins were found to be altered in nerve tissue from horses with grass sickness – most of which had not been previously linked with the disease – compared with animals that had died from other causes.
This knowledge could help in the development of tests for detecting the condition in horses, which can be tricky to diagnose.
Around 2 per cent of horses die from grass sickness each year in Britain. The disease occurs almost exclusively in grass-fed animals, including ponies and donkeys. A similar condition is thought to affect cats, dogs, hares, rabbits, llamas and possibly sheep.
“This is the first study to show similarities between an apparently unrelated neurodegenerative disease of large animals and human neurological conditions,” said Dr Tom Wishart, from the University of Edinburgh’s Roslin Institute, who led the study.
“Although the causes of these conditions are unlikely to be shared, the findings suggest that similar mechanisms could be involved in the later stages of disease.”
The research was funded by The Equine Grass Sickness Fund. The Roslin Institute receives strategic funding from the Biotechnology and Biological Sciences Research Council.
Proteomic Profiling of Cranial (Superior) Cervical Ganglia Reveals Beta-Amyloid &
Ubiquitin Proteasome System Perturbations in an Equine Multiple System Neuropathy
Bruce C. McGorum, R. Scott Pirie, Samantha L. Eaton, John A. Keen, Elizabeth M. Cumyn, Danielle M. Arnott, Wenzhang Chen, Douglas J. Lamont, Laura C. Graham. Maica Llavero Hurtado, Alan Pemberton, Thomas M. Wishart.
First published September 13, 2015, doi: 10.1074/mcp.M115.054635
The full study can be read here.