Yeah they're pretty good. Try to balance them more. See how close his toe is from being clipped by the frame of the pic on the bottom? Try and get equal spacing from top to bottom. And when you focus on a particular part of the horse (head, ears, etc.) make it the focal point but allow some "empty space" around it.
Also don't be afraid to play around with the camera's settings.
That's a good start and pretty horse.
#1: The lighting is nice, but as sky said, leave the same amount of room at the top and bottom
#2: Cute facial expression and nice positioning in the frame (with space to one side). Try to give him/her more space, the lower lip and ears are cut off.
#3: You are taking the picture from above the horse's level downwards. Try going lower, with you camera at the horse's height, keeps the proportions better. Posted via Mobile Device