I agree with Mark, this is an excellent action shot of both the horse and the dog.The colours are great as is the focus. I have always been very scared of horses, I'm even more so now! lol
A good picture indeed. The only comment I would make is that a slower shutter speed would have allowed a little more of the dynamic nature to come over as I feel that it is too sharply in focus. But, to get a shot like that so well framed is still very good.
Regards,
Mark.
Plymouth, UK.