WHY SPAY YOUR FEMALE?
By Wendy Brooks, DVM
A female dog spayed before her first heat will have a near zero
chance of developing mammary cancer. After the first heat, this
incidence climbs to 7% and after the second heat the risk is 25
percent (one in four!). It is easy to see that an early spay can
completely prevent what is frequently a very difficult and
potentially fatal form of cancer.
But is it too late if a dog is already past her second heat? No,
in fact spaying is important even in female dogs who already have
obvious tumors. This is because many mammary tumors are stimulated
by estrogens; removing the ovaries, the source of estrogens, will
help retard tumor spread.
Spaying removes both the uterus and both ovaries and is crucial in
the prevention as well as the treatment of mammary cancer.
The female dog comes into heat every 8 months or so. There is a
bloody vaginal discharge and attraction of local male dogs. Often
there is an offensive odor. All of this disappears with spaying.
WHAT IS PYOMETRA?
"Pyometra" is the life-threatening infection of the uterus that
generally occurs in middle-aged to older female dogs in the six
weeks following heat. The hormone "progesterone," which primes the
uterus for potential pregnancy, does so by causing proliferation
of the blood-filled uterine lining and suppression of uterine
immune function. It is thus easy during heat for bacteria in the
vagina to ascend to the uterus to cause infection. The uterus with
pyometra swells dramatically and is filled with pus, bacteria,
dying tissue, and toxins. Without treatment, the pet is expected
to die. Despite her serious medical state, she must be spayed
quickly if her life is to be saved.
THIS IS AN EXTREMELY COMMON DISEASE OF OLDER
UNSPAYED FEMALE DOGS!
PYOMETRA IS NOT SOMETHING WHICH "MIGHT" HAPPEN; CONSIDER THAT
IT PROBABLY WILL HAPPEN.
The older unspayed female dog has an irregular heat cycle. There
is no end of cycling comparable to human menopause. If you still
decide against spaying, be very familiar with the signs of
pyometra. (These include loss of appetite, lethargy, vomiting,
excessive thirst, marked vaginal discharge).
NOW THAT WE KNOW WHY IT IS A GOOD IDEA TO
SPAY, WHAT EXACTLY HAPPENS?
It is very important that the patient has not been fed in at least
8 hours. Anesthetic medications commonly induce nausea and
vomiting can be very dangerous in a sedated patient (vomit can be
inhaled/aspirated leading to pneumonia).
A preoperative evaluation is performed; blood work is recommended
for older females. An intravenous catheter may be placed to
facilitate the administration of anesthetic drugs, for any fluid
administration, and for use in case of emergency. This
necessitates shaving a small patch of skin on one of the legs.
Should you notice such a shaved patch, this is undoubtedly from an
A tranquilizer or other pre-anesthetic medication may be
administered to ease the induction of anesthesia. A special
medication is given intravenously to induce sleep. This medication
is called an "induction agent" and lasts only long enough to
establish the maintenance of anesthesia by the inhalant anesthetic
(gas). Once the pet is asleep, an tube is placed in the throat to
insure that a clear airway is maintained through out the
Sometimes a cough is noted for a couple of days after surgery.
This may have been caused by the tube in the throat. Such coughs
only last a couple of days; anything that persists longer should
The tube is hooked up to a special machine to deliver a specific
concentration of inhalant gas mixed in 100 percent oxygen. A
special technician is assigned to the monitoring of this pet so
that the concentration of inhalant gas can be changed, color,
heart rate, respiration and other parameters are followed.
In the surgical prep area, the abdomen is shaved and scrubbed. The
bladder is emptied and the patient is moved to a surgical suite,
where she is draped with special clothes or papers to isolate the
area where surgery will take place.
An incision is made on the midline of the abdomen, and the three
points where the ovaries and uterus attaches are tied off and cut.
The abdomen is checked for bleeding and two or three layers of
stitches are placed to close the incision.
It is helpful to know that should the skin stitches come out,
there are two layers below holding everything closed. Sometimes
skin stitches are not placed but if they are present, you will
need to return in 10-14 days to have them removed.
The anesthesia technician continues monitoring until the pet dog
wakes up and coughs out the throat tube. The patient is kept in an
observation room until she is able to walk.
Our hospital feels strongly that a night in the hospital is
important to an uneventful recovery. This night in the hospital is
analogous to strict bed rest, just what you would expect to be
needed after a major abdominal surgery. This night also allows for
proper administration of pain medication for a longer time period
as well as a post-operative check up with the doctor the morning
Our colleagues at the Ocean Beach Veterinary Hospital in Longview
Washington have put together a slide show demonstrating the spay
surgery. To see this slide show click here
WHAT TO EXPECT AT HOME:
Most spay patients go home the next day as if nothing had happened
though some will need pain medication for a few days.
Some nausea may occur in the first couple of days after surgery
and it would not be unusual for the pet to refuse food for a day
or two after surgery.
As noted above, a cough may persist for a couple of days as a
result of the throat tube. This should not persist longer than a
couple of days.
Dogs who show a propensity to lick their stitches will need an
Elizabethan or "E" collar to restrict access to the stitches. This
is not very comfortable for the dog but must be used strictly
until the stitches are out and the incision is healed.
Activity should be restricted during the week following surgery.
Excessive activity can lead to swelling or fluid accumulation
under the incision. If a fluid pocket does form, it should resolve
on its own after a few weeks. If a fluid pocket forms and drains
liquid from the incision, the dog should be re-checked with the
SPAYING IS ONE OF THE MOST IMPORTANT
PREVENTIVE HEALTH MEASURES THAT
CAN BE PROVIDED FOR A FEMALE DOG OF ANY AGE.
WHAT ABOUT BEHAVIORAL CHANGES?
The female dog's reproductive tract is dormant for most of the
year. It only activates for the three week period of heat. This
means that from a behavioral stand point, the female dog acts
spayed most of the time. It is unlikely that any change will be
HEALTH BENEFITS FROM SPAYING ARE
TOO IMPORTANT TO IGNORE.
PLEASE CALL FOR SPAY SCHEDULING FOR YOUR FEMALE DOG.