I saw a post by yOrkiesROck and she said that she paid extra to have the vet use ProPoFlo to induce her dog, Kash, and then they used Isoflurane.
I have also read 'Shooters' questions and answers and she talks about anesthetics although I am not sure how up-to-date her answer is. This is the link, anyway:
Alex's Yorkie Care Frequently Asked Questions. Page 3.
Hope the link works!
Hope your little furbaby copes well with the surgery and is soon back to his old self.
Luv
Franceen