over all this is a very nice, sweet peace. i like how you took the boy ad his dog idea and gave it a very slight twist.

you can see the love for the boy in the movement of the dog which can be hard to do with animals good job. the boy also had a very natural and smooth movement to him that doesn't feel like you had any trouble with the pose.

i do find some of the coloring on the dog to be lost against the background, feel that you sort of lose the third leg against the brighter parts.

and some of the fur looks a bit to fluffy, and it makes it had to tell if the general shape on the dark spot on the dog is the lost leg or the leg behind it

i also don't like the lines running across the top of the image i feel that it doesn't fit with the other parts of the picture i feels like a last minute choice.