Locking hind leg

[brightmount]

My daughter was lunging her horse this evening and phoned to say her hind leg was locking for a millisecond each time she brought it through.

The horse has been funny about this leg in the past for the farrier, and we had her checked over by an osteopath recently, who found nothing major going on, but at her suggestion we had the saddle checked and reflocked. She is not lame and never has been.

My daughter thought the locking was in the hock, but I thought more likely the stifle, though I didn't see it as I wasn't there, and she agreed it could be. I told her to give a loading dose of the joint supplement we have for the other horse, and we will see how things progress, and maybe get the vet out.

Does anyone have any ideas? The horse is a 7yo ISH, a great jumper, and was doing dressage at the weekend with nothing untoward.

 

[sare_bear]

When a stifle locks the stifle and therefore hock (work in unison), do not flex and so the horse appears to drag the leg. Known as upward fixation of the patella, part of the stay apparatus, that allows the horse to sleep standing up. In severe cases the horse cannot move the leg. As the ligament releases the leg suddenly over compensates and snaps upwards (over flexion). Are these the signs in a milder form?

It is more common in those horses that have a straight conformation behind or weaker hindlimb musculature. By carefully building up the horses exercise and doing hill work this often improves/self resolves. What level of work is your horse in?

I would consult with your vet to confirm that this is what is going on if it continues.

 

[brightmount]

She's in full work, ridden 6 days a week and well muscled. Odd one isn't it, as it was every step and just momentary. A horse on the yard that had classic locking stifle use to come out of his stable in the morning with his hind leg stuck out rigid. However in ridden work he was fine.

Hope it's nothing serious, the horse needs a new home next spring/summer as daughter is off to uni, and she was coming on brilliantly as an eventer

 

[Butterbean]

Was the leg locking straight or was the hock bent when it locked? Was it in one particular gait or in all? Did the leg swing out to the side or step under?

 

[brightmount]

Oh dear I don't know... my daughter is at work - I'll ask later. But I think the hock was bent as it was just after the foot left the ground, and I think it was in trot. Anyway, the horse was freeschooled this morning in the round pen and seemed OK in all gaits, so we'll have to keep an eye on things and see how it goes.

I'm putting her on a joint supplement to be on the safe side.

 

[Booboos]

I think you need to get the vet out.

There are a number of causes of a locking patella and some, although by no means all, are symptoms of more serious problems. I had a horse competing BD novice/elementary, making it to the regionals, but turned out he was bilaterally lame behind because of OCD and no one had noticed until his stiffle locked. However, I am sure he was a rare case and there is nothing seriously wrong with your horse, but I would have a vet check her over just to be sure.