The muzzle should be more sloped and the head less round. I wouldn't use a circle tool to draw it out. (I know you're doing basic shapes here, but maybe draw the circles free hand as a sketch sort of thing? )
The ears are good, but maybe they could be moved further back along the head? I've made them bigger too, but that's just my personal preference. Really, it just depends on what sort of canine it is.
The back should curve around more, with the part below the leg in the same place as where the part above the leg is. The shoulder shouldn't be that big or circular either.
The neck should come in a bit more, as the dog is looking down so some of his face will be pressed into the neck. The fur flows the right way, so that's good
You've got all the basic shapes there, there's just a few little changes, nothing major. Hope this is helpful!
