Anesthesia
Q: Is it true that the anesthesia procedure is the riskiest part of
surgery? How safe are anesthetics used in veterinary medicine?
A:
Tremendous advances have been made in the use of anesthesia during
the last decade that greatly in crease safety during surgery. Many
of the anesthetics used in veterinary medicine are the same as those
that are used in human medicine.
More
pets probably die each year from health problems that aren't corrected
surgically because of fear of anesthesia than those that die as a
result of the dangers of anesthesia itself.
A
pre-anesthetic workup is critical before any surgery. This consists
of a thorough physical by a veterinarian and often includes a blood
test and urinalysis. In some cases, X-rays and an electrocardiogram
are recommended.
These
tests are necessary to make sure there aren't underlying medical problems
such as kidney or liver disease, diabetes or chronic infection that
would put the patient at greater risk during surgery. Also, the tests
help the surgeon determine the best type of anesthetic procedure to
use.
The
rule of thumb is that the older the pet and the more severe the problem,
the more thorough the pre-anesthesia workup should be. Proper monitoring
of anesthesia helps to improve the safety during surgery. Many veterinary
clinics have an ECG or heart monitor which constantly checks the patient's
heart rate during surgery and warns if there is a problem. Also, trained
veterinary technicians usually help the surgeon monitor the pet's
respiration, color, eye reflexes and the level of anesthesia.
Gas
anesthesia is generally considered to be safer than injectable anesthesia
for most surgical procedures, since the gas levels can be increased
or decreased quickly as needed.
One
of the newer anesthesias available today is isoflurane. This gas provides
a high degree of safety with very low toxicity. Isoflurane doesn't
alter the patient's heart rate or blood pressure, and the pet wakes
up very rapidly after surgery. This gas is an ideal anesthetic for
older pets or surgery patients that have other medical problems such
as heart, liver or kidney disease.
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Pre-Surgery
Tests
Q: My dog needs some surgery, and our veterinarian has recommended
some blood tests before the operation. Why is that necessary?
A:
Your dog probably will have a total body function blood test before
receiving a general anesthetic for surgery. This is a very important
precaution to determine if your animal's organs are functioning properly
and if there are any other hidden medical problems.
One
part of the blood test consists of getting a complete count of the
numbers and types of white and red blood cells. This helps to determine
whether your pet is normal and healthy or has underlying problems,
such as anemia, possible bacterial or viral infection, allergies,
parasites or even cancer.
For
example, if your dog is anemic, the number of red blood cells will
be low, and they might appear pale under the microscope.
If
the immune system is suppressed, the number of certain types of white
blood cells can be low. With bacterial infections, the number can
be higher than normal. If leukemia is present, large numbers of unusual
white blood cells can be seen under the microscope. Allergies and
parasites can cause an increase in a specific type of white blood
cell, and sometimes microscopic parasites can invade the blood cells,
or the cells can change shape or size when various other diseases
are present.
Another
part of the blood test is called a chemistry panel. Certain chemicals
in the blood change if major body organs such as the liver and kidneys
aren't working properly.
For
example, if your pet has kidney disease, toxins begin to build up
in the blood because the kidneys aren't able to filter them properly.
Certain levels of chemical enzymes also then build up in the blood
if the liver is not functioning properly. Therefore, it is possible
to test the function of both the liver and kidneys by measuring these
chemicals in the blood.
High
blood-sugar levels can indicate a lack of production of insulin by
the pancreas, resulting diabetes. Diabetes can have many complications,
such as rapid cataract formation and low immunity to infections.
It
is also very important for electrolytes, such as sodium and potassium,
to be at proper levels and in balance. Certain diseases greatly change
these electrolytes, causing life-threatening situations. Persistent
vomiting and diarrhea or hormone imbalance in the adrenal glands can
cause an electrolyte imbalance, which would show up on the blood chemistry
test.
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Spay
& Neuter
Q: When do you recommend that dogs and cats be spayed or neutered?
Will this change their personalities?
A:
Dogs and cats usually are spayed or neutered as early as 6 months
of age, although many veterinarians prefer to wait to neuter male
cats until they are about 7 to 9 months old.
The
main purpose for spaying and neutering animals, of course, is to prevent
unwanted pregnancies. Many of the homeless puppies and kittens from
these accidental litters suffer neglect and eventually are destroyed.
Neutering
male dogs and cats also can help prevent unwanted roaming and fighting.
Sometimes this can make a pet more affectionate to the owner and much
easier to live with. In addition, the surgery reduces the risk of
prostate disease and various types of tumors.
Female
dogs or cats will be healthier and look better without unwanted puppies
or kittens. Spaying females when they are under 1 year of age will
dramatically reduce the chances of breast cancer later in life.
Female
dogs and cats that have not been spayed are at risk of developing
pyometra, a life-threatening medical emergency where the uterus becomes
infected. Any change in your pet's personality after being altered
will be from the natural maturing process, rather than a result of
the surgery.
Another
concern is that the pet might gain weight. After being altered, some
animals need fewer calories. The amount of food they receive should
be adjusted by the owner depending on the level of activity and rate
of metabolism. A male dog that is fighting and carousing needs more
calories than after he is neutered, when he is content to stay closer
to home.
For
both spay and neuter surgeries, a general anesthesia is used. Your
veterinarian will advise you about the importance of a preanesthesia
blood test, depending on the age and health of your pet. This test
can help determine how safe the surgery will be for your pet and sometimes
indicates the need for using a special anesthetic.
To
help avoid complications in your pet's spay or neuter surgery, make
sure that the operation will be performed in a sterile surgery room
by a licensed veterinarian.
After
surgery, most veterinarians prefer to have patients recover overnight
at the hospital, except for some male cats that might be sent home
the same day.
