Well, I was going to make the same point that boricuaqueen327 just made. Presumably you'll be shown an estimate including a line item list of what will be done and a consent form. If you have questions or concerns about what is going to be done, it's your responsibility to communicate that to your veterinarian ahead of time. I'm always happy to go over our anesthetic protocols, the specific drugs we would use, what they do, side effects, etc. It's surgery. The owner should be comfortable with what is happening to their pet.
If an owner refused analgesia for their pet (even after we discussed the benefits), we would refuse to do the surgery. I didn't become a veterinarian so that I could torture animals on the whim of an ill-advised owner. Think about the times that you've heard of people receiving surgery without analgesia. Usually it's related to some form of torture. If you tried to have abdominal surgery without any pain meds, my guess is you'd have a hard time finding a surgeon and an anesthesiologist willing to perform the procedure. First do no harm.
Here's the obvious benefit: when your pain is controlled you can rest comfortably, eat, and keep yourself hydrated, all of which is important to the healing process. I've had surgery and I've given birth and I controlled my pain after both of those events. I wasn't out running a marathon because I felt! so! great! But I was kept comfortable so that I could heal. That's just logical.
If you still don't believe me:
American Animal Hospital Association. American Association of Feline Practitioners. AAHA/AAFP Pain Management Guidelines Task Force Members. Hellyer P. Rodan I. Brunt J. Downing R. Hagedorn JE. Robertson SA. AAHA/AAFP pain management guidelines for dogs & cats. Journal of the American Animal Hospital Association. 43(5):235-48, 2007 Sep-Oct.
Pascoe PJ. Better therapies for everyday pain: exciting advances in pain management. Veterinary Journal. 166(3):215-7, 2003 Nov.
Hansen BD. Assessment of pain in dogs: veterinary clinical studies. [Review] [59 refs] Ilar Journal. 44(3):197-205, 2003.
Exciting times in veterinary analgesia
Veterinary Anaesthesia and Analgesia, 2003, 30, 1^2
The Management of Animal Pain Where Have We Been,
Where Are Now, and Where Are We Going?
The Veterinary Journal 2003, 165, 101–103
"Studies have shown
that the stress hormones such as cortisol and ACTH
will be elevated without the concurrent presence of
an analgesic along with anaesthetics in many cases
including those _simple_ elective procedures."
I've yet to see anyone here provide any evidence that pain is good for animals. Current standard of care is to provide analgesia, so the burden of proof is on the other side.
Honestly, I'm really surprised by the attitude here. I assumed that most people on this forum would be like our clients since I work at a holistic, bond-centered practice. But our clients have been, with no exceptions, very concerned about pain in their pets. I guess I'll go give them all big sloppy kisses for being so proactive with their animal's welfare. I thought they were the rule, not the exception.