Common leg problems: Splints
By Your Horse
27 November 2009 14:32
See a swelling on your horse’s leg and your first reaction might be to panic - will it take ages to mend, cost me a fortune and potentially affect his future? But don’t panic. With good management, most leg problems can be prevented and early intervention from your vet will more often than not lead to successful treatment.
What are they?
The term ‘splint’ refers to a bony enlargement of the inner (medial) or outer (lateral) aspect of the canon bone. The horse’s canon bone is bordered by two smaller, narrow bones, known as the splint bones. There is a strong fibrous attachment between each of these bones. Any strain of this attachment will cause inflammation, which results in the formation of new bone to stabilise the damaged area. The condition is most commonly seen in young ridden horses during the early stages of training as the limb is subjected to force. Conformation defects such as ‘bench knee’, where the canon bone is shifted to the outer aspect of the knee when viewed from the front, will place additional stresses on the skeleton and may make splints more likely. Direct trauma to the splint bones and/or the canon bone can also result in new bone formation. The swellings are most often seen in the inside upper third of the canon bone. This is because of the larger weight bearing function of the inner splint bone.
Diagnosis and treatment
In the early stages, the swellings are often hot and painful when touched, and associated with obvious lameness at trot. Occasionally you might not be able to feel the splint, even thought there is damage to the fibrous splint bone attachment. These are known as blind splints – radiographic investigation will aid diagnosis. Further investigation is also needed where new bone growth is formed close to the knee joint, where arthritis may result, or when it encroaches on the suspensory ligament at the back of the canon bone. In most cases the heat, pain and swelling will reduce after the initial inflammatory reaction has subsided. Some hard swelling will remain but this is usually only of cosmetic significance. Your vet may recommend a variety of treatments. The priority in the acute stage is rest and anti-inflammatory medication. Prolonged rest or surgical removal may be required in chronic cases where there is suspensory ligament involvement.
Prevention is aimed at the careful introduction of training in young horses, especially if they have conformation problems that make splints more likely. Protective boots will help.