I have a 17 month hanoverian filly. About 3 weeks ago she had some swelling in her LH fetlock. It was slight and lasted a couple of days but she never was lame on it. I'm not sure if this has always been the case because I didn't really notice it until we had the swelling incident but she is always resting that leg. Whenever she is in the cross ties and even in her coggins pictures she is resting that leg. I have noticed that when I am brushing her she will pick that leg up like she's going to kick but I always reprimand her to put it down. Yesterday when I was grooming her she kicked back with that leg a few times but not at anything. I thought she might be getting annoyed with the Show sheen driping from her tail onto her hock. Also, when I pick the hoof up to clean it she makes no effort to "help me out" if that makes sense. But she does with the other 3. She was trotting beautifully and sound this afternoon. She is big (15.1ish) and stays in at night. My vet will be out tomorrow on his routine visit which he does weekly. I can't decide if he needs to look at her because I may just be paranoid or it could just be a growing thing.
I sold a 3 year old several years ago that didn't pass his initial PPE because the last hind leg they flexed, he objected to. I'd been riding this horse off and on all winter prior and he showed no lameness or any grouchiness. This was March and vet passed it off as he slipped in some mud, wait and see yada yada. Well after a couple weeks of playing with different ideas, my chiropractor was there to do the "spring tune up". He looked at this guy and right away said his hip joint was "out of whack" for lack of the real official sounding term he would have used. He popped him back in and within a week, he was letting me pull that hind leg up tight with little or no objection and he was sold, and shown in reining early the next year and to this day is fine. After the problem was found, I figured out how he'd done it. He'd and couple others had been spooked out of their large loafing stall and ran outside. Rather than turning to go out a side gate, he went straight and half jumped the other gate, catching that hind leg over the top and bending the gate down... so he would have stretched it backwards really hard. Other than some hair scraped off, I didn't notice any issue at the time.
Anyway, I'm suggesting you look up high. Good luck
My horse is fine, moves just as pretty as she can and my vet as well as my trainer think I'm nuts. Better to have the piece of mind though so I will pay for that. She was a perfect child also so that was nice. I am now "that" mom. I am so relieved. Thanks for the advice to get my vet to check!