Empaul02, what you describe sounds like an infection tho from my armchair here, it is only an impression, not Gospel. The more we inject, the greater the chance for something to go south, regardless of skill level/experience. Joint infections from injections are NOT the norm. Life… stuff happens. With horses, it happens more often. x 10.
I have not had personal experience (in any of MY horses) with an injection gone bad yet (touch wood) but know of several (4) clients who have. The recovery was moderate in time spent tho the horses all recovered satisfactorily and went back, however briefly, (at this point, dialing down for a couple of them was the practical and humane way to go, the other two are still working well) to their mid to upper level jobs. Again, a watchful eye…
I do hope that this is an isolated incident for you and your girl, that she is over it soon and that you are back out together : )
Sure there's right and wrong but mostly there's just a whole lotta different.