Muzzle:
A dogs muzzle is not too square and has a slight curve at its bottom and it's jawline is not visible so far back normally (it rather converts to fluff nearer the back of its neck) when drawing it's snout take into account that it is not all one thing and picture it as two things separated by the mouth. Draw down from its nose and curve it into it's mouth then start the bottom jaw moved slightly backward from the mouth.
Ears:
A dogs ears arn't too curved at the back and face frontward rather than curving away from the way the dog is facing, remember to add the inner part of the ear too and don't make the ears too big.
Neck:
It depends on which dog you draw for the neck, whether it's a fluffy dog or short-haired dog, some dogs have longer necks to others so I go by how fluffy the tail is, if the tails fluffy I make the neck fluffy too, if the tails short-haired, draw the neck using plain lines curved where it meets the body. Just be sure not to make the neck too thin or long.
Legs:
A dogs legs are not plump but be sure you do not make them too thin, you can emphasize detail by adding slight 'bone' outlines were the paw meets the leg. As you did originally it's knee is near its stomach and is only a little higher than its back leg knees. Be sure you don't make these joints too rounded and make them a little more square.
Body:
Your body was quite long compared to the legnth of it's legs and remember dogs don't really have that 'hourglass' stomach, it's wide at the ribcage and gets thinner towards its stomach (unless it's a rather overweight dog
) So just make sure it's body is not so thin and doesn't get wider toward the back, the legs will do that.Tail:
The tail is overall quite good just as I mentioned above if the necks not fluffy the tail shouldn't be 'too' fluffy but who doesn't like a bit of fluff
Sorry if it's a bit complicated, I kind of confused myself and it came from my mind xD but I hope it helped none the less
