This article is from the Canine Medical Information FAQ, by Cindy Tittle Moore with numerous contributions by others.
Remember that this is not intended as complete information by any
means. Your best source for that is from your veterinarian. Don't be
afraid to ask questions. IVC had a great article on anesthesia.
How dangerous is anesthesia?
While anesthesia is not without risks, it is most certainly not
guaranteed death for your dog. Your vet anesthetizes dozens of animals
a week without losing them, and your pet should be no exception. There
are a number of different anesthetics available, each with their own
benefits and risks:
This is just about archaic and should not be in much use any
more. Some vets still use it because it is inexpensive, but it
is not as safe as newer anesthetics available today.
Probably the most commonly used. It is a good general purpose
anesthesia which is simple to control. A drawback is that it
takes animals up to an hour to completely wake up from it and
they usually behave sedated for up to another 12 hours. The
only real reason to use it now is that it is less expensive
Extremely safe, produces complete anesthesia for any type of
surgery and it is not metabolized by the kidneys in the same
manner as halothene or methoxyflurane.
What can I do to improve the odds?
The greatest danger from anesthetics is improper processing of the
drug by the dogs metabolism. All these anesthetics are eliminated from
the blood stream through the liver and kidneys. Older dogs in
particular can have defects in these organs that can cause
complications under anesthesia. If you are concerned about this your
vet can do a preliminary blood panel to detect potential problems. If
your pet has a heart murmur or a respiratory problem make sure your
vet is aware of it. These are not necessarily problems during
anesthesia, but will allow your vet to make an informed decision
should a problem arise. You should also ask your vet if sie knows of
any problems peculiar to your breed. Sighthounds in particular are
more sensitive to anesthetic and require lower levels to achieve the
same effect. Make sure that you keep a complete medical history of
your dog and that you take a copy of it with you whenever you change
Why is anesthesia used for OFA X-rays?
Most Xrays can be taken without any sort of sedation, but OFA Hip
X-Rays require certain amount of stretching and twisting of the legs
to get the hips into a proper position. Most dogs will struggle from
the handling (or in some cases, pain if they are dysplastic), and the
resulting X-rays can end up blurred. While for many cases this would
be OK, OFA requires very sharp images. It is possible (as has been
mentioned here often) to get acceptable X-rays without sedation or
anesthetic, but it requires a lot of work and experience along with a
cooperative dog and this may miss some borderline cases.
Other anesthesia pages