For me, quiessence has worked amazingly! But, that still didn’t make my pony completely calm, relaxed, and not tense (and I am definitely not one of those people who likes horses that act completely drugged up–I just mean not nervous and jittery!) Depo works amazingly, but your horse may not need it. Depo is a hormone injection, and it is NOT drugging or anything like that–there are reasons for humans to take this as well! It has majorly reduced my pony’s anxiety, and it was clear that this was a hormone that his body needed. Like I said before, some horses already have plenty of hormones in their bodies that depo is supposed to assist. But, it is definitely worth a shot! And please, since your horse is injured, if at any point his nervousness and hyper-ness becomes a danger to him, call your vet to have him sedated. It can save his life!