Page 372 - The Veterinary Care of the Horse
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lameness in some horses.
VetBooks.ir Oral administration of nutraceuticals – see page 230
Extracorporeal shock wave therapy
Some horses which fail to improve with medical therapy do improve following shock wave
therapy. This is considered to be due to an analgesic effect rather than any affect on ankylosis
of the joints.
When medical treatments fail to resolve the lameness, more invasive techniques can be used.
These include:
Surgical arthrodesis
This technique involves drilling out some of the articular cartilage of the distal intertarsal and
tarsometatarsal joints so that bridges of bone form across the joint space and immobilize the
joint. The technique has a better success rate for riding horses than for competition animals,
particularly dressage horses where hock action is crucial. In one study, 59% of horses were
able to return to their former level of performance. Most horses recover within 6 months but
some do not become sound for up to 1 year.
Chemical fusion of the distal hock joints
Injection of sodium monoiodoacetate into the distal hock joint spaces causes degeneration
and collapse of the articular cartilage, allowing the adjacent bones to fuse. Suitable cases
have to be selected carefully to ensure that the distal hock joints are not in communication
with the proximal intertarsal or tarsocrural joints. (Communication between the synovial
cavities of the hock joints of horses is variable.) Treatment with sodium monoiodoacetate can
be painful for the horse.
Ethyl alcohol is also used to accelerate damage to the articular cartilage and speed up
fusion of the distal hock joints. It is reported to have a 70–95% success rate and the horses
usually improve within 3 months.
Cunean tenectomy
The cunean tendon runs obliquely across the medial aspect of the hock. Removing a section
of this tendon results in an improvement in some horses. This was considered to be due to a
reduction of pressure on the medial side of the distal hock joints where new bone was
