A FEW weeks ago I received a call from a client who reported his horse was lame for a few days on a front leg. He said that there was swelling around the tendons at mid-canon level and that he had hosed and bandaged the leg and applied cooling agents to try to reduce the swelling.

Apparently despite his efforts, the level of lameness was increasing. He was very concerned and was convinced that the tendons were damaged. He wanted me to scan the tendons and diagnose how bad the damage was; propose a treatment and advise as to what would be the likely prognosis.

When I arrived at the stables, I examined the gelding and just as the owner had reported, there was indeed extensive swelling at the back of the leg at mid-canon level. On palpation, this swelling was thick and painful. It was difficult to distinguish the tendons from each other.

We took the horse outside. He was visibly lame at the walk and the lameness was more pronounced at the trot.

While examining the leg, I decided to work from the bottom up and so I started by examining the foot.

I cleaned out the sole area and applied the hoof tester. Much to our surprise, there was a marked response to the tester and the horse pulled back from the pressure, indicating pain. I pared away at the area gently with a sharp hoof knife.

After about one minute, pus oozed through a spot in the sole indicating the release of an abscess. I opened up the area to encourage as much drainage as possible and applied a wet poultice to the foot.

The owner was delighted to see that it was an abscess rather than tendon damage.

The horse was poulticed for five days and the swelling in the leg came down gradually over that time. As the horse improved, he was able to tolerate increasing amounts of exercise.

FOOT ABSCESS

In this type of case, swelling, if it is seen in the leg, is most often in the fetlock area.

However in some cases like this one, the swelling can be higher up the leg and can cause confusion.

The swelling is caused by increased blood supply travelling down the leg to the foot due to presence of the abscess there. When this blood does not return back up the leg as quickly in the venous system, fluid moves out into the surrounding tissues causing swelling.

Occasionally if the foot abscess is severe, infection may move up the leg causing a painful swelling. Normally once the abscess is released from the foot, the swelling in the leg will recede fairly quickly.

What can be learned from this incident is that simple cases of lameness can cause confusion.

An interesting fact is that approximately 70% of front leg lameness cases involve the foot so therefore it should always be checked as a matter of course even if initially it does not seem to be involved.

Normally in the case of a foot abscess, the level of lameness will increase on a daily basis until the pressure is so much that the horse points the toe as it becomes increasingly more painful to put the sole of the foot on the ground. There is not always evidence of swelling in the leg and, if swelling is present, the level of swelling can be from very little to severe, as in this case.

SEEK EXPERT OPINION

If you are presented with a confusing case, it is best to phone your veterinary surgeon or farrier who can discuss the facts of the case with you and help you to figure out what is happening.

If there is any suspicion of an abscess, it should be checked out as soon as is possible so that there is less of a chance of the abscess doing any damage inside the foot or an infection travelling up the leg.

The horse in this case made a full recovery and was back in full work within two weeks.

Denis Doyle MVB MRCVS is a veterinary surgeon in Wicklow town and is a member of the Equine Group of Veterinary Ireland

Email: hq@vetireland.ie

Telephone: 01-4577976