I recently had to give my horse a course of antibotics via needle. I was switching between either side of his neck and either side of his chest. He took the needles fine but recently I found that one side of his chest, were he was given a needle maybe two days ago, has began to sag down. I'm not sure what has happened, as far as I know the needle was given correctly. Should I be worried?
I can get pictures if anyone would like.