8 Feb 2024
It is hoped the method will aid a greater understanding of how horses at the highest risk can be best identified, diagnosed and managed.
Paul Imrie
Job Title
Research in Thoroughbred horses has found animals with lower levels of collagen type III have a higher risk of fracture.
Previously, research into fracture has been limited and no genetic mechanisms had been identified, but new findings by researchers at the RVC have enabled them to develop systems that identify genetically high-risk horses.
It is hoped the scoring system will aid a greater understanding of how horses at the highest risk of fractures can be best identified, diagnosed and managed.
Although Thoroughbred racehorses are prone to problems due to the forces exerted on their bones, fracture is complex and environmental and genetic risk factors can affect a horse’s susceptibility.
Debbie Guest, senior research fellow at the RVC, and her team developed a polygenic risk score, which provides a measure of disease risk due to a variety of genes, and used this to determine the distribution of scores across the general UK Thoroughbred population.
This data was then used to select cells from horses whose risk placed them at the extreme ends of the population in terms of risk. The cells were then used in studies to establish a cell model and investigate genetic factors involved in fracture risk.
It was this research that found collagen type III is expressed at lower levels in bone cells from horses with a high genetic risk of fracture. This was due to a change in their DNA sequence in the region controlling collagen III production.
The team said additional research was now needed to validate the scoring system in another cohort, and further studies using the system and cell model will help identify other genes and processes that impact on fracture.
Dr Guest said: “The development of a polygenic risk score for fracture will allow us to identify horses that are at high genetic risk to allow the targeted use of diagnostic imaging and close monitoring of their bone health.
“This study has also demonstrated the power of using cell models to work out what differences exist in bone cells from high and low-risk horses – and, therefore, why some horses are at high risk. This is vital to develop new interventions for high-risk horses in the future so that they are less likely to suffer from a catastrophic fracture.”
Research was funded by the Horserace Betting Levy Board, the Anne Duchess of Westminster Charitable Trust and The Alborada Trust, and is published in Animals.
