Here's some addtional lyrics and the original words to a couple of different sections:

2nd verse:

Well, I handed the man fifteen dollars about
and said, "I'll just stick him in my shirt and head on out
and reached for the one who looked like a little fox
He said, "You hold it right there and fill out these sheets
have him back in here for shots in a couple of weeks
and it's our policy you take him outta here in this box!"

3d verse:

Then he folded up a cardboard crate in a minute
took my dog and stuck him down in it
pushed on his head and folded in over the top.
I can hear him yet how he scratched and he cried
and he hollared some more when I got him outside
and we were almost home before he decided to stop.


Last line of TD's version verse 3:

And he taught me when to say NO! and I needed that.

Part B of the 4th verse: (TD's original version)

When I've fallen asleep and and I want to roll over
I always think twice about wakin' up the rover
I mean, after all I wouldn't want to wake my dog up!

Tag line after last verse:

Yeah, the whole thing started 'cause it looked like fun
Everybody else had a dog. I wanna get me one I said
and have a little friend around the place.

The original version on 'A Delicate Balance' the dog is a female. So if one wants to remain true to the original include the changes above and change the gender as well.