Ugh, another issue. I've had Jazz on lease for a little over a month now. In the past three days, I noticed something odd. On Saturday, after I rode him, I removed his tack, and started to brush him down, and that's when I noticed it. 'It' is a small bump, about the diameter of a penny, somewhere around 6" down his back from the withers, and to the left of his spine. It is not squishy, but does not seem hard enough to be a bone either. I poked and prodded and put pressure on it, and his expression didn't change, nor did he flinch, so I don't think it is painful for him, so I decided that it was probably no big deal, but to keep an eye on it. When I went back today (Monday), I felt all along his back, looked at it from every angle, and the offending lump seemed to be completely gone. I was very pleased. We went for a short ride (about 30 minutes) of light jumping, cooled out, and came back in. I untacked him, and there 'It' was again - the lump. Same size, same location.
The saddle that I have been borrowing from his owner does not fit him. It is two wide in front, and fits completely weird - I bought a half pad for it, which I thought had resolved most of the issues, but I'm pretty sure that this has to do with saddle fit, since it is only appearing after I ride him, and then resolving itself before the next ride. Now, the saddle doesn't fit, but it's problem is that it is too wide, particularly in front - and it does not come anywhere near touching his spine (or just next to it) in any way, shape, or form. I have two hypothesis' about this. #1 is that it is a pocket of liquid in response to a pressure point (perhaps even next to the lump, pushing it over, who knows), #2 is that it is a muscle misplaced by the pressure of the saddle.
I just bought a new saddle (got a like-new, name brand cheap off of ebay), and I'm praying it will fit him. I won't find out until next week though, because that's how long it takes to ship the saddle from Florida, to Ohio. So, in the meantime, I'm obviously not going to ride him in that saddle. We'll do some lunge line work, maybe take some walks (weather permitting), and I'll spend the rest of my allotted time with him giving him massages and generally spoiling him. I don't really mind not riding, I just love to spend time with him - my first and foremost concerns are his health and comfort. All of my local horse people that I have asked so far agree it's probably the saddle, but have no idea what exactly is going on - this forum has never failed me yet, so, does anyone know what this could be???