Dr. Elaine Norton, an assistant professor at the University of Arizona College of Veterinary Medicine, has made it her mission to bridge the gap between human and animal welfare by studying complex genetic traits in horses. Her work on equine metabolic syndrome (EMS) aims to transform the equine industry and contribute valuable insights into human health.
Equine metabolic syndrome is a significant health issue because of its role in causing laminitis, a painful hoof condition leading to costly medical treatments and, often, euthanasia. This syndrome affects a significant portion of high-risk horse populations. Yet, disease management regimens remain highly focused on generalized diet and exercise protocols that may fail to address the individual needs of affected animals. “The lack of understanding of the complex relationship between genetics and environmental factors is a barrier to effective treatment,” says Dr. Norton. Her research strives to uncover the gene-environment (GxE) interactions that influence EMS, offering the potential for more personalized management plans that could improve treatment outcomes and prevent laminitis.
Unveiling GxE Interactions in EMS
Funded by the USDA National Institute of Food and Agriculture, Dr. Norton’s primary research project involves investigating the GxE interactions contributing to EMS using a multiomics approach: incorporating genetics, transcriptomics, metabolomics, and epigenetics. This comprehensive method will provide new insights into the environmental triggers that interact with genetic factors to manifest EMS clinical symptoms.
Dr. Norton highlights the broader implications of this research: “EMS in horses is remarkably similar to metabolic syndrome in humans, which is a risk factor for diseases such as heart disease and type 2 diabetes,” she explains. Metabolic syndrome affects 1 in 3 adults in the US, and while genetics play a role, the complexity of environmental factors can obscure clear treatment pathways. Because horses serve as naturally occurring models for metabolic diseases, studying EMS could help overcome challenges encountered in human research and could have significant implications for improving human health.
Exploring Maternal EMS and Its Impact on Foal Health
In collaboration with Dr. Jane Manfredi at Michigan State University and funded by the Grayson Jockey Club, Dr. Norton is also investigating the effects of maternal EMS on foal health. With an increasing number of broodmares affected by EMS, there is growing concern about the impact of maternal health on fetal development. Current management practices often involve maintaining higher body condition scores in mares to ensure adequate nutrition for foals, but the long-term implications of this approach are unclear.
Research in this area is crucial because maternal insulin dysregulation in humans—such as gestational diabetes—can lead to a higher incidence of complications like premature birth, dystocia, and metabolic diseases. Dr. Norton and her team are exploring whether similar issues occur in horses with EMS, specifically focusing on how maternal EMS may influence placental function and foal health outcomes. “Our preliminary findings suggest that mares with EMS exhibit the same histological changes in the placenta as women with gestational diabetes,” she notes. This parallel opens the door to using horses as a model for understanding and addressing gestational diabetes, which could ultimately lead to improved treatment options for equines and humans.
Dr. Norton’s innovative research continues to broaden our understanding of equine metabolic syndrome and its potential implications for the broader One Health initiative. Her work emphasizes the interconnectedness of human and animal health, providing insights that could improve equine welfare and human healthcare in the long term. As we deepen our understanding of GxE interactions, the future of precision medicine in equine and human populations looks promising.
