Page 404 - The Veterinary Care of the Horse

quadriceps muscle tone. The exercise programme will depend on the age and type of

horse. Very young animals can be walked in hand. The recommended exercise for older
VetBooks.ir animals is walking and trotting in straight lines. They may be led or ridden as
appropriate.

• If the horse is sore, non-steroidal anti-inflammatory drugs such as phenylbutazone may

be administered.
• The animal should be turned out rather than stabled.

• If the horse is debilitated for any reason, this should be addressed. The diet should be

checked and routine worming and dentistry carried out.
• If the limb remains locked, it may release if the horse is walked backwards. If not, then

the vet will try to dislodge the locked patella manually.

A youngster should be allowed to mature if possible before any further action is taken. When
the above measures do not provide relief, then the following options may be considered.

• Injection of the medial patellar ligament(s) with irritants to tighten the ligament.

• Surgical cutting of the medial patellar ligament. This procedure is called a medial patellar
desmotomy. It is usually performed under local anaesthetic in the standing horse, under

sedation. The technique is rarely the first option because of complications that have been
reported following surgery, e.g. persistent low-grade postoperative lameness and

fragmentation of the patella.
• An alternative procedure has been developed for treatment of upward fixation of the

patella. The upper third of each medial patellar ligament is split while the horse is either
sedated in a standing position or under general anaesthetic. Horses begin in-hand walking

exercise the day after surgery. Immediate resolution of the condition is reported in some
cases, in others it takes up to 2 weeks. The healing process causes the ligament to
become 2–3 times its original thickness and this stabilizes the joint and prevents the

upper part of the ligament from catching or hooking easily over the medial ridge of the
femoral trochlea. No long-term complications have been reported.

PROGNOSIS

The prognosis is good when the condition resolves as the horse becomes fitter. Occasionally
the condition will recur if the horse loses fitness and condition or needs box rest for any other

reason.
The prognosis is reasonable for horses undergoing medial patella desmotomy if care is