Royal Veterinary College research points to possible new osteoarthritis treatment for horses

Researchers at the Royal Veterinary College, working with University College London, Middlesex University, the Institute of Cancer Research and the University of Oxford, have identified a protein called CDK8 as a promising target for treating osteoarthritis. The study, published in the journal Bone Research, tested a CDK8 inhibitor in mice, human tissue and equine cartilage cells, and found it reduced the abnormal cell changes that drive the breakdown of joint cartilage.

Osteoarthritis is thought to affect around half of horses over the age of 15, and there is currently no approved treatment that can slow or reverse the disease rather than simply manage its symptoms. In the mouse studies, animals treated with the CDK8 inhibitor showed improved gait and exercise capacity, better cartilage structure and fewer of the bony changes associated with disease progression. Equine cartilage cells responded in a similar way in laboratory tests, suggesting the same biological pathway is relevant to horses as well as humans.

The researchers describe the findings as an encouraging early step rather than a ready-to-use treatment, and say further research and proof-of-concept studies will be needed before any drug based on this approach reaches horses, dogs or people. For owners and vets, the main significance for now is scientific rather than practical: it points to a genuine gap in current care, and a plausible new direction for closing it, at a time when joint disease remains one of the most common welfare and soundness issues in older horses.