For an anxious, watchy, spooky, nervous, high-strung, jump, reactive horse? I need input from those who have actual experience with one of these drugs or another that maybe I haven't heard about. 

I had a horse on Prozac that was spooky and reactive, and it helped him a lot.  I was able to take him off it after a few months.

Do you remember how you dosed him?

Fluoxetine HCI Capsules 40mg, 2 capsules, once a day. 

My vet gave me one syringe with 4cc in it. Supposed to last a month. I think it made him worse.

That might've been fluphenazine. I've known people to use it and not work.  My vet prescribed the fluoxetine.  The pharmacy name is Covetrus. 

Prozac (fluoxetine). Vet said he has better luck with Prozac. A friend  gives a very small dose of reserpine weekly. She's happy with it. Guess I need to call him back.