"Hmmm." The storekeeper's finger stops just short of pressing the button. "As nice as you look, sheepdogs are a lot of work. You'll have to be brushed a lot. Anyway, I think I'll do you a favor and pick something with a longer life expectancy. Sheepdogs are only good for 8 or 9 years, and you're already giving up most of your life."
You halfway understand what he is saying. Your master is going to make you live longer! He is a good master! But then something else finallyconnects. You've given up most of your life? Of course! Memory returns. You're a human teenager! Or were. Which means you will die maybe fifty years sooner than you should!
The store manager presses some buttons,a d you feel yourself shift. The hair in front of your eyes fades. You master looks thoughtful. "German Shepard. Very nice. But they have hip and heart problems. Let's see..."
You want to run away, or maybe attack him before he can make the final save that will turn you permanently into a real dog. But the loyalty factor is too high - you cannot do anytyhing to harm him, or even make him unhappy.
"Ah! Perfect!" He makes another entry, and you change again, this time getting a little smaller. You feel heavier, though, and your legs get stronger. "A large mix-breed! Mutts are always the healthiest animals. Oh, and I should take care of neutering you here - saves expense for me and pain for you later."
He clicks another option, and canine sexual equipment you never even had a chance to see is gone. You don't feel any pain, and the idea of sex is oddly hard to conceive of now.
"There. OK, boy. You're about to be re-written permanently as my dog!"