The woman smiled as she looked over at you, "Not to worry, your girlfriend seems to be enjoying it, don't you my dear?" She asked. The lab bitch looked over at you and wagged her tail before letting out a bark. You barked back happily as she barked again, then the woman had her collar in front of you, "Sit."
You opened your mouth and let out a bark as you sat down in front of her. Your head tilted up as she leaned forward, "Good boy," she said as she slipped the blue collar over your head and tightened it around your neck. It was weird at first but it soon felt normal as you felt something hard push up your ass and out of the hole that had formed. It was a tail, yours had grown in and you could feel the tip of it pushing against your backside.
You looked down and saw black fur starting to grow over your body as your feet changed into paws. Your strange human hands turning into dog paws as well, you let out a bark as you saw yourself changing. Your arms and legs becoming the limbs of a dog, your body changing into that of a large black lab. The last things to change were your head, which became a muzzle as your ears grew pointed, and your crotch.
You had been naked as you changed, and now you could see your penis growing smaller and smaller until it was a little bump, a knot of flesh with a small slit in it. You could feel the weight of something hanging below it as you looked down and saw a dog's scrotum forming. It hung down between your legs as your balls dropped into it, you could feel them forming into the shape of dog testicles.
You panted happily and wagged your tail as you finished changing, barking happily at the woman who had done this. She had turned you and your bitch into real doggies, the two of you looked like a pair of dogs as she smiled.
"Good dogs," she said as she petted you both. "Now, let's get you to the dog park, I'm sure you'll both love it."
You wagged your tails and barked happily as you followed the woman out into the back where she put you in a car and drove you to the park. It was filled with all sorts of doggies, from little tiny ones to great danes and everything in between. You wagged your tails and barked happily as the woman let you out.