It's time for your kitten to be spayed, or your elderly dog to undergo a much-needed teeth cleaning. At the vet's office, you watch Fluffy disappear behind a door, hoping your pet re-emerges a few hours later a little groggy but good as new.

While most dogs and cats are tolerant of anesthesia, each time it is used there is a risk, however small.

All the more reason why, when it comes any procedure involving anesthesia, you need to ask questions. Some factors to consider:

* Pre-op exams. "I've had people say they favor a certain practice because the vet doesn't charge for exams," says Alicia Z. Karas, assistant professor of clinical sciences and a board-certified anesthesiologist at Tufts University School of Veterinary Medicine in North Grafton, Mass.

That kind of thinking is shortsighted, she says. "A thorough exam, even of young dogs and cats, is important," allowing the vet to pick up abnormalities such as a heart murmur or signs of anemia. Simple blood tests also can identify risk factors and are especially important for older animals.

* Monitoring. It's a legitimate question to pose to your vet: Who will observe my animal while you perform surgery?

"Having somebody watch the animal, his respiration and some form of monitoring of his heartbeat -- that's number one," says Arnold Lesser, a board-certified orthopedic surgeon based in New York.

Many practices have electrocardiographs and pulse-oximeter machines, which measure oxygen saturation in the blood. In addition to inquiring about who will be attending the vet during surgery, Lesser says, it's fair to ask if a vet will use those two pieces of equipment.

While Karas says short-handed practices might use monitoring equipment as a substitute for having a person there, "pulse-ox and EKG can give you misleading information. If you had a human being listening for heart and breath sounds, that would be best."

Simultaneous human and mechanical monitoring is optimal -- as is an observer who has some training in anesthesia, although in many practices, the vet tech fulfills this role capably.

* Anesthesia. There are two categories of anesthesia: induction and maintenance. Induc-tion anesthesia is injected to get the animal unconscious. Today, many vets still use a combination of Ketamine and Valium. The newest injectable agent, Propofol, is quicker-acting, but it can depress breathing, and it is significantly more expensive.

In the past, ultra-short-acting barbiturates were common induction agents, but are rarely used now.

During surgery, an animal is kept unconscious with a maintenance anesthetic, which is inhaled. Isoflurane is commonly used in many practices. Sevoflurane, which is relatively new and correspondingly expensive, is especially fast-acting -- a double-edged sword if a practitioner is not paying close attention.

For a quick surgery, such as a cat spay, some vets might be tempted to use just an induction anesthetic. But with the exception of cat neuters, owners should insist on inhalant anesthesia as well, because the animal is intubated -- something that's invaluable if the unexpected happens.

"If there is a problem, say a bad reaction, having an airway established beforehand is a big safety factor," Lesser says.

* Pain management. "Pain management is something people are paying more attention to," Karas says.

With the exception of dentistry, teeth cleaning and wart removal, most animals should require at least one post-operative dose, she says.

Denise Flaim is a reporter for Newsday, a Tribune Publishing newspaper.