"Cool," Derek said with a grin, "I told you I should be first. So am I going to be a Great Dane, Alsatian, Golden Retriever, Pit Bull or a Sheep Dog?"
Sonya came over and opened the collar and began to put it around Derek's neck.
"You're too eager, besides this is a test remember? I think I'll try something smaller, cut you down to size," she said with a wink.
"Oh, no, you're not turning me into a purse dog," said Derek, as he tried to pull free from the collar, but the buckle locked in place.
"Yeow--oooooow," howled Derek as his skeleton and muscles cramped up as he began to shrink and reshape from human into a small dog.
Derek dropped to forward to his knees, and raised his arms upward as the joints changing made them snap forward. He stared down as his hands came to a rest at Sonya's feet. The four digits were shrinking as his hands became paws. His thumb twisted around to become his dew claw. He yelped as the muscles stretched to accommodate their new position. He lurched forward as his chest collapsed into the traditional barrel shape of a canine torso. His eyes teared up as they rotated away from his nose slightly. His irises widened to fill his eye sockets. Then he felt a pain in private parts and arched his back as his half erect cock which had been tugged down the leg of his boxer briefs became canine which required the shealth to attach to the underside of his belly. The fabric of his underwear was getting in the way. He bucked, and shivered as his organ worked itself into the right position. Then he felt his spine elongate. The clothing he was wearing was starting to get heavier as he shrank. His t-shirt arms now were touching his paws, and to his relief his shrinking body slipped out of his formerly tight jeans. The t-shirt collapsed like a tent around him. So he couldn't see how his body was changing, or what it was changing into. He blinked as the color began to fade from his view, and he snorted as the new scents he was smelling began to overload his senses. No wonder dogs saw in monochrome, the myriad of scents he was taking in each had their own color.