I like the bottom left photo on the top picture. Nice catchlights, good expression. I think a kicker light is really essential for black on black photos (whether it's a dog or a shirt or hair.)
But for me, the rest look accidental, the type that would probably get deleted right away. The good news is, they look better than your last photo shoot. Keep practicing!
Can you explain accidental please?
And thank you. I won't give up.
Sure.
What I mean is, it looks like you were randomly pressing the shutter button without waiting for "the moment."
Remember that when you're taking pictures of pets, we humans like to project human emotions and personalities onto them. Therefore, even though their facial structure is vastly different to our own, we like to look for similarities.
Look at all of your pictures and try to imagine a human face. Would it be a keeper if the man were looking off, not paying attention, not engaging the camera, or with no emotion on his face? Of course not. That's why it doesn't work with the dog in the three other pictures in the top square.
The two large black photos both have us looking straight up the dog's nose. Again, imagine a human tilting his head back so we're staring at nose hairs. Not attractive.
As for the last one, I understand what you felt you were capturing...the dog showing love for the stuffed animal. And in the moment, it's possible he was. But in the picture, he's just looking at it. It's not a terrible picture, and if not for the flare I'd have kept it too. But it definitely doesn't quite capture what you were looking for, and with the technical problems on top of that if throw it out.
Now look back at the bottom right of the first picture. Like I said, it could be improved with a kicker to separate him and a reflector on the dark side just so he doesn't melt away into the background. Imagine a human face there. He's engaged, he's focus, he looks cheerful and natural, his chin is down so we're not looking up his nose. That's the kind of thing you should be looking for. Flattering light, sparkling catchlights, natural expressions. Humans and posed pets are photographed in very similar ways, so studying up on portrait photography could help a lot. Running dogs are photographed more like sports, which it sounds like you're used to. I think you'll agree that sports and portraits are two very different genres, even if they're of the same person, and someone who wants to do both with have to study techniques for each.