New tendon research could help prevent and treat injuries

The discovery that ageing causes significant blood vessel loss in equine tendons could help identify horses at risk of injury and the best way to treat them.

The Royal Veterinary College research considered imaging of the superficial digital flexor tendon, and found that older horses – those aged between 18 and 22 – showed a 70% reduction in vascular volume (the amount of blood present in the tendon blood vessels). They also found a reduction of 30% in vessel diameter, and 74% in the number of vessels, compared to horses aged between two and five.

“This means older tendons receive far less blood flow, making them more vulnerable to damage and slower to heal,” an RVC spokesperson said.

“At the same time, the team observed an increase in the formation of smaller blood vessels within aged tendons, suggesting that the tissue attempts to compensate for the loss of larger vessels. However, this new vascular network appeared disorganised, indicating a loss of vascular balance, so the normal structure and coordination of blood vessels is disrupted. These changes suggest that the new disorganised vessels may not function effectively, reinforcing the need to monitor tendon health closely as horses age.”

The team was led by post-doctoral researcher Nodoka Iwasaki and lecturer Chavaunne Thorpe.

“This study used advanced 3D imaging to reveal, for the first time, how the blood supply to the horse’s tendon changes with age,” Dr Iwasaki said. “We found that older tendons lose many of their larger blood vessels, which are crucial for repair and recovery. This helps explain why older horses are more prone to tendon injuries and why these injuries heal more slowly. We are now exploring ways to prevent this age-related decline, with the aim of improving outcomes for older horses diagnosed with tendon injury”.

Dr Thorpe added that the team is developing methods of slowing the age-related declines, which “if successful, may improve prognosis in older horses diagnosed with tendon injury”.

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