I can't see much of a lighting issue on the Lucky shots but with his face being the flat type, be careful not to meter off his nose area when focusing which is very dark otherwise the rest of him will be blown out. Meter off a mid tone on his face and you can lift the shadows in photoshop if needed.

The only other things are to avoid wide angle at all costs. It distorts and looks horrid unless you are using it specifically to get an artistic type of distortion. It's always better to get a bit further away from the dog and then zoom in than being too close and having to zoom out. The second one of Giselle demostrates this distortion quite a lot. Look at how tiny her body is compared to the over-sized head in it. The first one of her is much better but try and be more observant as to backgrounds so that you don't have destracting objects like the fence sticking out from behind her etc... Also, be careful of overly bright skies behind dark ears...as you can notice with her ear that sticks up being bled into by the brightness.
Secondly, never take photos looking down at them. Easier said than done with small dogs but photos where you are looking down at them are unflattering for the dog to say the least and will never be anything other than snapshot quality. If you need to buy waterproofs to lay on the ground, so be it and get laying on the ground...

I know, lots of criticisms but I get the impression you wanted to get better photos so these are just helpful suggestions. Happy snapping.