The changes did not stop there, and the new golden retriever barked and whimpered as he felt a tight aching in his groin. Whining exactly like a dog, unable to form words to express his discomfort, Jeremy rolled over onto his furry back and craned down to see what was happening.
One rear paw twitching, Jeremy saw his pointed red canine dick throbbing and aroused, yet somehow shrinking. Bruno padded closer, watching intently as Jeremy's maleness grew thinner and shorter, receding into his body. He felt a tight ache in his furry balls, as if he was wearing extremely tight underwear, before with a slow and bizarre sensation, they were sucked up into his body.
Unknown to Jeremy, his former testicles moved and reshaped inside him, pulling up wards to form a fully functional canine womb. He felt a strange change inside him, but that was secondary compared to the terrifying feeling of seeing his manhood fully recede, and feeling a strange, warm wetness in his crotch as it gently opened up into a canine vagina.
Bruno seemed to be grinning as he moved closer in. Jeremy's ears twitched as he picked up his dog's scent, a strange new tantalizing aroma that he somehow instinctively recognized as that of an aroused male.
Jeremy found himself panting and hot, his new pussy wet as it oozed a scent in return, that of a needy bitch in heat. He forced himself to resist his bizarre instinctual desires, struggling to cry out, but only barked and growled like a beast. Rolling over onto all fours, he moved to run, but struggled to control his new quadrupedal stance.
As he hesitated, Bruno took his chance. Jeremy felt the hot, heavy furry bulk of the golden retriever pouncing onto his back, pressing down on top of him. Bruno's warm doggy breath huffed onto his head as the dog's erect red cock searched at Jeremy's groin, until finally the former human gasped as he felt a warm, thick length sliding into his sensitive new organ.
Panting and dazed, Jeremy was awash in pleasure as Bruno began humping him, mounting him doggy style. A part of him was appalled, that he was being taken by his own pet, but a much stronger part of him was loving the feeling of being bred, each hard thrust making his moist inner walls flood with pleasure.
Jeremy closed his eyes, considering trying to struggle, but he wanted more. He began thrusting back into the pounding penetration of Bruno's fucking, soon making the dog's knot swell and harden, before Bruno pushed forward harder, and Jeremy's ears perked up in shock as he felt the swollen knot stretch his pussy, tying them together.
There was a pause that seemed to last forever as Jeremy's mind came sharply into focus, and he realized his situation. He had turned into a bitch, and was being mounted by his own dog, and he was about to climax. But his horror and shock was suddenly washed away as Bruno began to orgasm, the dog pressing down on top of him and suddenly howling loudly. Jeremy felt the hot sticky fluid rushing up inside him, and he shivered as orgasms rocked his own body, his pussy milking his dog's thick rocket for all the cum it could. His resistance was washed away in pleasure, and he howled alongside his dog, gladly accepting what was happening.
It was a long time before Jeremy and Bruno managed to get untied. The former human tottered unsteadily on his four strange legs, as Bruno nuzzled his head. It was hard to think, to remember ever being human, and being a dog felt so good. Which was good, because somehow he knew that with the quickening inside him, the slow growth of his and Bruno's pups, he may never be able to turn back.