Dale had taken a seat and shifted uncomfortably side-to-side holding his tail. He wasn't exactly regretful he'd changed himself, at least not completely. He just sort of wish he'd listened to the doctor warning him what a drastic change a tail this size would be. ('A 45-year old man knows what he wants!' -- hah!) Maybe something shorter would have been easier to deal with after all. But Dale wanted a rat tail and now he has to live with it.
"Well, let's the rundown over with," said the doctor, suddenly approaching. He reached out a hand in front of him. Dale eyed the doctor's hand dumbly for a second and figured out what he was asking. He handed his new tail over and felt its weight get taken by the doctor's gloved hands. He found himself hoping the doctor would be careful with it.
"What's hanging out of your butt now is well over a meter now long, not far off from two. It's got a significant internal anatomy that you need to be aware of. Obviously in the middle of this is your spinal column. But underneath that, here under the middle here, is your ventral artery. Should be nestled in there pretty good, but be careful. You got blood running a LONG way down now."
That bit of info really gave Dale some pause. A lot of his circulatory system was quite literally in the doctor's hands right now. Dale would have to take care that the blood going down his new major artery made it back up the other way.
"Up here on the left and right, you've got the dorsal veins. I've already warned you that you might not be as prepared for the length and appearance as you expected, so I'll just go ahead and let you know some benefits you might not have known you were getting either."
That caught Dale's attention.
"First, you'll probably be more aware of your surroundings. It might even feel almost like you have eyes in the back of your head. You're going to be able to sense a WIDE AREA behind yourself, now. Rats use their tails as sensory organs and to orient themselves in space, in fact their whiskers can play a similar role, but you didn't want those. But one extra perk you might not have noticed yet is you can probably start buying less deodorant."
"Really? But ain't I gonna sweat even more with all this extra skin--"
"No. Quite the opposite. Those major blood vessels I told you about can change size as needed. They can pass a LOT of blood -- and therefore a LOT of heat -- in and out of this large, poorly insulated surface area. Your tail is like a radiator."
Dale suddenly noticed that he didn't notice the temperature in the room. He'd sweated a lot while he was growing his tail, but he felt perfectly comfortable now.
"So, my body temperature is affected, by having a--"
"--a built-in heating and cooling system sticking out of your ass? Yes. Thermoregulation is thought to be one of the reasons rats have the kinds of tails they have."
Dale couldn't take his eyes off of what the doctor was holding. It wasn't just a fantasy anymore. It was going to play an important, and potentially useful, role in his life from now on.
"M-may I ... ?" Dale spoke up slightly.
The doctor looked back down at what he'd been pointing out the veins in. "Oh, um, yes, of course," he agreed, handing it back to its rightful owner. Dale received it back into his arms without too much fanfare, looking over it and trying to memorize its anatomy: spinal column, dorsal veins, venti--ventibal--no--VENTRAL artery. He focused on it, focusing a desire for motion toward the distant reaches of his spine. And with that, it launched itself out of his grasp to land beside him, dangling over the side of the chair toward the floor. Dale stood up and swung his tail around a bit more, straining his neck a bit to watch it move.
Satisfied that he could probably get used to his massive new tail, Dale faced forward again and shook the doctor's hand. "Well, I wasn't sure I was ever really goin' through with it, but it looks like I've made it! Thanks for all your help, doc!" The doctor had a gleam in his eye, returning the firm handshake. "Any time. Animalia Incorporated is available for all your transformation needs. Just take it easy for a few days and don't forgot what I've told you!" Dale gave the doctor a friendly parting smile and made his way out the door, swishing his long new tail behind him.