Do not let your vet use this anesthesia. Isoflurane and Sevoflurane are much more expensive for the vet to use, but dogs come out of anesthesia very quickly. If you let your vet use the barbituate anesthesia there is a strong possibility that your dog will not wake up!
Read this link and be sure and scroll down and read about Buttons, may the little one rest in peace.
http://www.shooterdog.com/alexfaq3.htm#SURG