It's early days but a new diagnostic method is causing excitement, says Peter Green MRCVS
When horses have tendon trouble we now expect the vet to “scan” the tendon.
All equine vets have portable ultrasound scanners with which they examine tendons in the legs on a computerised image. Dark patches represent areas where the normal tight fibres of the tendon have been disrupted or torn and replaced by looser areas of bleeding, fluid and weaker tissue.
Ultrasound scans are commonplace. Magnetic resonance imaging (MRI) is less common but increasingly available for diagnosis of tendon trouble where the ultrasound scanner cannot reach — inside the hoof capsule, for instance. But MRI scanners are very expensive and are not portable.
A recent report has investigated a new technique for assessing leg tendons. Elastography is a development of ultrasound scanning in which specialised computer software generates an image based upon the softness or firmness of the tissue being scanned.
Instead of showing a grayscale screen image of the “echo” of the tendon, as ultrasound does, the screen shows a colour image based upon elasticity of the tissue being scanned. Very soft areas are yellow or red, very firm areas are blue or green.
The technique is used in human medicine to distinguish between benign and malignant tumours. Vets at Davis in California have tried it out on horses’ tendons with very encouraging results. The exciting thing is that the equipment is not necessarily massive and hospital-based — it can be portable.
Availability may be some way off, but it looks likely that horse vets of the future will not only be taking ultrasound scans of dodgy tendons but “elastograms” as well.
Picture by W. Rich Redding and Gabriela Seiler