Hey everyone, to clarify...the bump is a collagen granuloma, caused by a bug bite...I actually had it biopsied weeks ago and tested and that's what they found it to be. She hasn't really been worked hard for about the last 2 months because of it (I couldn't put a saddle on her back because of where it is located and after they biopsied, there were stitches there of course).
We just started easing her back into some jumping recently, starting with just a small flower box, then cross rails, then 2'0" - 2'3". So this height was not anything out of the ordinary for her, it's just that this particular day she was acting funny over the 2'3" line and not the 2'0" vertical in the middle of the arena.
NEW DEVELOPMENT though...may have found the actual issue! I went out to hand walk her today and was having her trot around...no issues...UNTIL we were on the hard driveway, when I noticed a very slight lameness. I had some friends watch me trot her from the front and the back and we discovered she is slightly off at a trot on a hard surface on her left rear/stifle area!
The muscle there is contracted and after we trotted her that little bit it was twitching for awhile too
We think she may have pulled a muscle there when she was jumping last weekend since the footing was questionable, and THAT was prob why she all of a sudden started jumping like that!
The vet is coming out tomorrow as a follow up for the bump, so I'll have him take a look at this issue while he's there...in the meantime I put some liniment on it. I'll keep everyone updated, and thanks for all the advice everyone!