After Damon finished howling, he simply sat and whimpered. When he was done whimpering, he simply sat still. When he got tired of just sitting still, he took a few cautious glances over his body, just to make sure everything had really happened the way he thought it did. When he was mostly satisfied that it had all really happened, he tried to ignore his body and tried to cling to his vanishing hope that he might still be hallucinating. He didn't like seeing his Rottweiler self, because it reminded him just how thoroughly he had been defeated. He'd only wanted to take the witch's heirlooms, but she had taken it all: his human life, up to and including his bodily existence as he knew it. He'd still be himself if he'd simply gone back to jail instead. Now, even if he managed to escape from the witch and go back to Chris and John, all they would see would be a dog--at best, a tough-looking animal they could sell for some nice bucks on the dog fighting market. Sure, he might not have been all that great as a person, but at least he'd BEEN a person. He'd known there was always the risk of getting shot or stabbed on a heist gone wrong or a drug deal gone bad, but even then, he would have been a dead or injured PERSON. Having every part of his body magically altered, and being forced to outlive his own humanity like this, was quite another matter altogether.
Admittedly, he did let his attention wander a few times to the one part of his body that HADN'T been altered, because it hadn't been there to begin with: his tail. His very own doggy distress signal! He already resented its betrayal of him in front of the witch, when it made him look just like the helpless animal he knew he was becoming. His tail was a permanent reminder of how much he'd lost, but it was still a gain in some sense. At least, it was something new that he'd have to learn to live with, and he wasn't fully acquainted with it yet. He could at least give it credit for one thing: now that he was no longer cowering before an imminent threat to his being, he no longer felt compelled to tuck it beneath him like an abused puppy. It was still rather unwieldy, but at least he was getting a chance to wield it more or less his own terms. He could even point it almost directly leftward, rightward or upward so that he could see it without having to look directly at his dog legs or his furry torso. He even found himself wondering if he could bring it right up against his face, maybe even get the long thing in his mouth; in an oddly tantalizing way, it would be like bringing his new existence full circle. He knew it wouldn't be easy to do so, but before he could try, he remembered some old viral videos of animals chasing their tails, and he refused to sink to that level, so he decided to ignore his tail, too.
Now that Damon was finished accepting that any part of his new body even existed, he just sat still and looked around. There wasn't much to see; he could see that he was still sitting in the witch's front lawn, but by human standards, he could barely even see that. His blurry, half-colored vision made the world look as drab as he felt inside. Of course, as a canine, he was now aware of far more of the world than he could see. Sniffing the air curiously, he realized it could take weeks for him to catalog the smells he was discovering, make sense of what they represented, and track their changes over time. Besides, his newfound ability to hear every conversation, vehicle, or animal within hundreds of meters had some potential to keep him entertained, even while he was tied up in one spot. But even the circus of sounds and smells around him was mostly just background noise except when something stood out as being worthy of his full attention. He soon managed to find himself as bored as he would have been sitting in his bedroom alone as a human. He almost wished he could actually scare off some intruders, just like a real guard-dog, simply to have something to do! He even found himself barking along with the neighbor dogs, in spite of his distaste for his new voice, simply to pass the time and socialize in some fashion.
And after Damon decided he was even done barking, he became increasingly desperate to do SOMETHING--anything--other than sit at the end of his leash on pins and needles. It was tedious work to NOT do things, just so he would NOT do things a lowly DOG would do. And Damon was really starting to run out of interesting new things to NOT do.