Marie is a lovely 4-year old grey mare. Her owner called our equine number very worried one morning because she had a horrible wound to the back of her pastern on the right front leg. The pastern is the bit of leg immediately above the hoof.

It’s amazing the damage a horse can do to itself despite the best care taken by owners to keep them safe. For some reason only known to Marie, she had decided to do some digging in the hedge that morning with her front feet…probably looking for some extra tasty plant that had taken her fancy. Unfortunately, buried deep in the hedge was an old rusty bit of wire that no one knew was there. Marie pulled her leg straight back into the wire, panicked and caused a nasty wound to the back of the leg.

The problem with horse’s legs is that joints, tendons and other important structures are often only skin deep. This particular wound caused me a great deal of concern because of its proximity to where the bottom of the digital flexor tendon sheath is. The tendon sheath is like a double-ended sock which wraps around the flexor tendons as they pass over the back of the fetlock. Similarly to a joint, it is a synovial structure, which means if any bacteria enters via a wound, it is extremely serious and will result in the sheath becoming septic and ultimately the horse having to be put to sleep due to unmanageable pain.

We commonly see these sorts of wounds in horses and it’s important we manage them appropriately to give the horse the best chance of recovery. This wound was absolutely filthy: mud from the hedge and rust from the wire everywhere. You can’t usually tell just by examining a wound if there is involvement of a joint or tendon sheath. In this case, I was highly suspicious, so I carefully cleaned the skin before placing a needle into the tendon sheath away from the wound in the top of the sheath (other end of the double ended sock!): I then injected sterile saline, filling up the sheath and sure enough, saline squirted out of the wound at the bottom. This confirmed that the wire had cut through the skin and into the tendon sheath, which meant bacteria would have been taken in as well, and this tendon sheath was septic.

Luckily for Marie, she had a very committed owner, who agreed to send her to horse hospital for surgery under general anaesthetic. Our team of equine vets can do most things at the yard, but arthroscopic surgery requires a theatre and hospital team. With the horse completely asleep in theatre, it’s possible to flush huge volumes of sterile saline through joints and tendon sheaths to clean them. ‘Keyhole’ type cameras and tools are used as well to inspect the inside of the joint or sheath to make sure there are no contaminants left and clean any damage. In Marie’s case, the surgery took hours longer than usual because all the bits of rust in there had to be picked off bit by bit.

Marie returned from hospital about a week later. After many days of bandaging and medicines, she has recovered very well from her ordeal and is hopefully set for a long and happy ridden career ahead of her.