The first thing out of the ordinary Tom felt was a twitching in his spine. He could feel it moving around at the end, like a little tail, something he hadn't felt since nearly ten years earlier when he spent a short time as a greyhound. Then he felt a surge of growth as it became longer, starting to rub up against the fabric of his clothes at the tip. He pulled his pants down and turn around. He was going to be stuck with the appendage for life this time, so he might as well watch it take shape and hope he could get used to having it. It swished around somewhat aimlessly as it grew from, taking on a distinct curve as it gained length and girth. It soon grew long enough to dangle past his knees if he relaxed it, which was one of the first things he tried when he started to gain control of it. He swished it around some more on purpose, knowing he now had already a part that would mark him as a true animal for the rest of his days. When long black hairs started to grow out of it, he stared intently as it became indistinguishable from a German shepherd's tail, hardly different from the one he'd given his wife.
Tom raised his furry tail so he could grab it, and got a quick introductory lesson in how not to hold it. He knew it was easy to accidently tug a dog's tail too hard or bend it too far and make the canine yelp or bite, but the sharp pain up his own spine still took him by surprise! It took all his effort to avoid shouting and avoid waking his daughter. After he managed a more gentle and relaxed grip, he ran his fingers through the bushy fur. It felt just like petting a dog would. He hoped there would be humans willing to pet and play with him in the future. He had at least given Samantha that much!
The fur growth was not stopping at his tail. He soon had black and brown fur all over his torso and spreading down his arms and up his neck. He let go of the tail and rubbed his chest for a while. It felt just like petting Samantha did, but it was all him. He felt some tingling in various places down his chest and explored those. His hands grazed some new bumps that felt odd. He quickly odd that the bumps he was feeling were his new canine nipples. He thought back to all the litters of puppies his wife had suckled--part of the life he'd doomed her too in a split-second moment of panic. He felt a twinge of guilt for leaving himself male! Too late to change that now, at least.
Tom heard a squishy gurgling inside his abdomen and then knotty twisting in his guts. He clutched his stomach and moaned softly, bending over a bit until it past, tucking his tail slightly in between his knees. He felt a tad dizzy when it was over, standing up and grabbing his head until he regained his balance. He stared down at his belly. His thoughts wandered to what was surely in there. There were some human foods he'd never be eating again. There were also some very disgusting things he would be able to digest now, things he would be expected to shove his nose into like any other dog. He hoped Samantha had eventually gotten used to that. He hoped he hadn't left her with too much of her human mind for that to be possible. (Of course, we know that's exactly what he'd done.)
He wasn't sure whether to examine his fur some more, try to get more accustomed to that giant tail flopping around, or go to the mirror and take one last decent look at his human features before his face changed. Maybe he'd be better off to just stop and try to ignore all of this until his next change happened. He was already biting his lips at the thought that he would almost certainly never live past his late fifties, and no one would know he had ever been anything more or less than a dog. The facts were starting to sink in for him, just as they had for Samantha all those years ago.