As the days went on, the dogs had begun to create their own civilization, lacking knowledge on how to work many human appliances, they ended up turning to an almost feudal state, using primitive spears and bows, and when the power plants stopped running, burning anything they found for fires.
But we don't care about that.
Tracy had in fact been impregnated by Tony, and after the frantic escape from the mall, the various humans began to try their best to retain their intelligence and society despite their new form, and the dogs having superior bodies, and intellect. It was slow, over the weeks, Tracy had lost the ability to read, and soon, her name. Little by little, her six nipples growing into six breasts that swaying and jiggled beneath her. She noticed of course, but didn't do much other than accept it, her memory of the past was fading too.
She was with her pack, out in what used to be Central Park, eating a deer that her pack had killed earlier, they'd made their den on the old playground , using the tunnels as shelter. Feeling a familiar feeling, she got up and trotted over to the edge of the bushes, and pooped.
Just a month and a half ago she'd be mortified to do this, but now she simply accepted it, and couldn't wait for her litter to be born!