Not crazy at all.

I worked at the track for years and we were sent a colt once with specific instructions not to let him out of the stall until he had been gelded because he was so unmanageable.

When the vet did the work he immediately saw one of the testes was very badly bruised and he said at the time we would probably see an immediate change in the horse's attitude. Doc said it was probably being bruised while the horse was moving on the track.

Sure enough overnight he turned into the gentlest,best behaved horse in the barn.

Take the pain away and anything can happen.