The compostion of your pet photos is excellent. Very very good for a beginner. One tip - and you want to use this for people also.... You want to focus on the eyes!
I like the pug photos.. especially the close up (no.1). Not too sure I like the horse ones..maybe you could zoon out a little and get a bit more of the horses face.
Like the attachment? I should be going to shoot horse jumping on Sunday. I love horses so I'm really excited about that. I'll post a couple of shots on Monday if you'd like to check in on them
The dog shots are awesome IMO. The last 2 cat pics are too soft of focus for me though. I agree that the horse pics could be better if you focus on the eye(s). Nice work!