I want to first apologize of I draw the wrong overall pose for this. I wasn't entirely sure if you wanted the character to be lying down or jumping, but I decided to go with lying down and I hope that that's correct.
My main critique for this would be to keep in mind what the neck and body are doing, not just the legs. You've drawn the legs pretty large and clear, but the neck seems to have been forgotten, and the body downsized to accommodate. Don't be afraid to make either one shapely. If you have a dog, you should observe how they look while sleeping-- or perhaps just look up references if you do not have one.
My second biggest critique would be that the hind leg seems a bit uncomfortable. For it to be in that pose, I think that it would help to turn the paw over to show the pads, so it looks more like the leg is relaxed on the ground instead of pulled away from the body. It might also help to show the over hind leg somehow, perhaps sticking out from under the belly.
Minor critiques I would have would be that the tail looks a bit high up, and that eyes can look a bit more natural if you draw "cone" shapes instead of complete circles while in profile.
Never stop drawing; always practice and don't be afraid to look up references and tutorials!
I have a ton of tutorials here if you want to give some a look: http://norisus.tumblr.com/post/41310512 ... masterpost
I hope that this helps!

