Q: What are capped elbows, hocks or knees?
A: A capped elbow, hock or knee is caused by an inflammatory swelling or distension of the bursa overlying the relevant joint. It is usually caused by trauma or prolonged contact with a hard surface e.g. the stable floor when lying down or the horse box’s rear ramp when travelling. The ‘capping’ is normally just felt as a soft, fluid-filled swelling that can be felt just beneath the skin. The horse is generally not lame, but unfortunately, capped elbows, hocks or knees can become permanent in some horses.
When a horse is stabled, rubber matting and deep bedding will help protect him when lying down. Capped knees or hocks can also be caused by repeatedly striking the stable door or walls, so padding them may reduce the likelihood of these problems. Legs in general, but knees and hocks in particular, should be protected when travelling by travel boots or bandages.
Note: If you notice swelling of your horse’s joint, do not assume that it is due to the joint being ‘capped’. Instead phone your vet immediately. Many serious joint and health problems can present with swollen joints.