Doc McArt laps at your cock, sucking and licking it and you feel it growing in his mouth. It's getting larger and it's growing down his throat, but he seems to be quite capable of taking all of your new man/bearhood.
Your changes are progressing and though part of you says you should run, another more dominant part of you wants to be complete. Deep bass grunts are coming from the Doc. You notice his clothes are getting really tight. You see that they are close to bursting with the new muscle being built under them. Doc's scent is changing too; his musk is growing more animalistic and it intoxicates you with each deep breath. You growl in a deep bass that matches the doc's.
"Yes," you think, "this is what I've wanted all along. Strength, hair and big balls."
Your muscles spasm as they grow, you look down at the doc when you hear a ripping noise and see that his lab coat and jacket and his silk shirt beneath that have ripped down the back revealing coal black fur over a broad muscular back.
You scratch under his furry changed ears with fingers that are quickly growing pads and claws.
"Oh, Doc." You growl huskily, "I love you." You growl deeply as you shoot your load down the doc's hungry throat.
Doc McArt looks up at you with big brown bear eyes and you see that he loves you just as much. He pulls off of you and licks you balls. He stands, much taller than he was mere minutes ago, and puts his arms around you.
"I love you too, Carl." He says and you're pulled into his strong embrace.
A mating bond is forming between the two of you. Your marvel at the changes in both you and Doc McArt. Your fur is dark brown and it looks like, though the Doc might be changing into an anthro Black Bear, you're becoming an anthro hybrid of Grizzly/Black Bear. Probably the effects of the Ursus Major formula mixing with the Ursus Magna formula you were injected with.
There's a timid knock at the exam room door...