species: click on a picture:
The best solution to uncontrolled breeding is spaying and
neutering. Spayed or neutered pets are happier and
healthier. They are not made tense and nervous by
unsatisfied sexual needs. In the case of females, they
never will develop certain types of cancer or uterine
infections. Preventing unwanted litters is another common
reason veterinarians recommend spaying. The best time to
spay is before the first heat: five and half to six months
for a cat; six to seven months for a dog.
There are several options for birth control. Please discuss
these options with your attending veterinarian as both
options have their benefits and risks.
The female reproductive tract
The reproductive tract of the female dog begins with the
ovaries where the ova
(or eggs) are produced. When a dog’s heat cycle starts,
hormones stimulate the maturation of some of the eggs. The
eggs are then released through the surface of the ovary and
pass into the oviducts.
These are tiny tubes that run between the ovaries and the
horns of the uterus. It is within the oviducts that
fertilization (the union of the sperm cell and ovum)
occurs. In the typical 40-pound dog, both horns of the uterus are normally
about four inches long and the diameter of a wooden pencil.
When the animal is in heat, their thickness will easily
double and they may lengthen slightly. The horns attach to
the body of the uterus,
a short common area where the horns meet. The uterus ends
at the cervix of the
dog. During pregnancy, most puppies develop within the
uterine horns, but one may reside within the body of the
There are birth
control pills and shots manufactured specifically for use
in dogs. Most of these products can have serious unwanted
side effects (pyometra). It shouldn’t be used in
animals intended for later breeding. That seems curious,
since most dogs that are going to be kept intact are
generally kept that way for breeding purposes.
control pills are not a viable option as a practical
permanent form of sterilization, the only option is
surgical sterilization. In the female, this would be either
• spaying (medically
referred to as ovariohysterectomy). A
female pet is spayed, a male pet is neutered. Both are
surgical procedures performed by a licensed veterinarian
while the animal is under anesthesia.
• hysterectomy, in which
only the uterus is removed. Removing
only the uterus allows us to prevent gestation, but the
female still keeps her ovaries, so she will still have her
• tubal ligation or
hysterectomie. Tubal ligation only affects the
oviducts. These are isolated and then cut and tied off with
suture material. This prevents the ova from coming in
contact with sperm cells or passing into the horns of the
uterus. In a hysterectomy, the uterus is removed, but the
ovaries remain. With either procedure, the hormones that
are normally produced by the ovaries continue to be
released to the rest of the body. This is fairly important
in humans. However, in dogs it is a disadvantage and she
will still have her heat cycles.
These are different surgeries, but each one will prevent
future pregnancies if done correctly. Only an
ovariohysterectomy should be considered for the long-term
health of your dog.
An ovariohysterectomy (OHE) or spay is the complete removal
of the female reproductive tract. The ovaries, oviducts,
uterine horns, and the uterus are removed. Not only does
this procedure prevent the animal from becoming pregnant,
it also eliminates the twice-yearly heat cycles. The
surgery removes the source of production of such hormones
as estrogen and progesterone. These hormones are
responsible for stimulating and controlling heat cycles and
play a major role during pregnancy. But they also have
other effects on the body and some of them are potentially
harmful (uterine infections, mammary cancer).
There is firm medical research indicating that if a
dog spay surgery is performed before the dog’s first
estrus cycle (heat) the chances for developing mammary
gland cancer later in life is nearly zero.
operation is performed under general anesthesia and employ
sterile instruments and a sterile surgical field. This dog
had a slight uterine infection, so we did an
The dog is
anesthetized and the fur is removed at the surgery site.
incision is made through the skin of the lower abdomen and
is deepened to the muscle wall.
ovaries (1) and the body of the uterus (2) are exposed and
This is an
of the uterus (a) below the uterine horns (a and b) is
isolated and sutures are placed around the blood vessels
and the uterus itself just below the
surgical area is examined thoroughly for any sign of
bleeding the operative site is closed in layers. The
peritoneum and abdominal muscles and subcutaneous tissues
are closed. The skin sutures are in place and once healing
has occured are removed in 8 to 12 days. Sometimes no
external sutures are needed.
Once the intervention
has finished, the animal will be transferred to a warm
room, placed in a stretcher on top of a table, in the
floor, or inside a spacious cage, covered with a blanket to
keep it’s body temperature constant. The veterinarian or
veterinary assistant (nurse) will maintain constant guard
on the dog until its fully awake, depending on the kind of
anesthesia the animal was under, and its metabolism. In
some cases it’ll be necessary to give antibiotics or other
protectors to the animal through a shot.
• Does sterilization make the dog gain weight?
No, neutered dogs will not get fat and lazy as long as you
keep up his excercise and don’t over-feed him. If we take
good care of the dog’s alimentation she will not gain
• Does sterilization modify the dog’s behaviour?
Female dogs are usually more calm and affectionate, but the
purpose of this operation is not the modification of her
behaviour. On the contrary it is the male’s castration,
which sometimes is necessary to deal with the dog’s
• Does the operation reduce the risks of breast cancer?
Spaying eliminates the possibility of uterine
or ovarian cancer and greatly reduces the incidence of
breast cancer, particularly when your dog is spayed before
her first estrous cycle.
• Does the female need to have puppies before the
Dogs are not concerned with maternity, so it
depends on whether you want your dog to have puppies or
not. Having a litter is NOT necessary for your pet’s good
health; this is a myth. On the other hand i you do choose
to allow your dog or cat to have a litter, please be
certain that there are committed pet caretakers waiting and
wanting to provide a home for them.
Spaying or neutering helps dogs live longer and healthier.
It makes happier dogs.
• When is the best age to alter my pet?
Most veterinarians recommend alteration prior to
the pet’s sexual maturity, between 5-7 months. A pet can,
however, be altered at any age, with special consideration
for any general health issues taken into account. The
earlier a pet is altered, the less risk of disease later in
life, and the easier and quicker he or she can recover from
• Can I have my dog spayed while she’s in heat?
It’s possible to spay a dog during estrus, or heat,
but it’s not the best time. Most veterinarians prefer not
to spay a dog in estrus because the uterine tissue can be
swollen, fragile, and more prone to damage. Dogs also have
a tendency to bleed more when they’re in heat. Because of
this, estrus makes surgery more risky for dogs, as well as
for cats. Most veterinarians prefer to delay spaying a dog
until she has been out of estrus for a month or so. And,
since a recently spayed dog may still be attractive to
males, performing the surgery during heat won’t do anything
to keep the neighbors’ dogs out of your yard. The best
thing for your dog’s health is to keep her safe inside for
now and to have your veterinarian perform surgery in a
month or so.
Should veterinarians do early neutering in their veterinary
hospitals? This is a question that is likely up to the
individual veterinarian. Since reproductive capability can
occur as early as 4 months in the cat and 6 months in the
dog it is important to neuter prepuberally.
Research at the University of Florida has compared
puppies and kittens neutered early (7 weeks) from
those neutered prepuberally but later (7 months) to
those that remained surgically intact.
• Growth plate closure
– Both groups of puppies and kittens neutered prepuberally
had delayed physeal closure compared to the intact control
animals. Longer radial and ulnar length was significantly
different in male puppies neutered at both ages and in
female puppie neutered at 7 weeks. The differences were
similar but not significant in kitten. Gonadal hormone,
facilitate maturation of physeal cartilage. Early neutering
does not stunt growth but actually may result in increased
long bone length because the absence of gonadal hormones
and the resultant delayed physeal closure. Some
veterinarians have suggested that early neutering will
predispose to physeal fractures (fractures through the
growth plates), however neutering at the usual time is also
prepuberal and delays physeal closure.
• Growth rate – No
• Food intake – No
• Back fat depth – No
• Body fat and weight – Neutered cats were similar in this
category but sexually intact cats weighed less and had less
• Urethral function –
Urethral pressure profilometry showed no adverse effects.
Male cats neutered at 7 weeks, at 7 months and the sexually
intact cats had similar urethral diameters at the end of
• External genitalia –
In dogs, the external genitalia of the “early” neutered
animals were infantile. No problems with perivulvar
dermatitis or vaginitis were noted. In cats, the external
genitalia of the “early” neutered kittens were also
infantile however, the problems with separation of the
balanoprepucial folds noted in earlier literature was not
evident. The penis in each cat could be exteriorized
indicating the balanoprepucial fold had separated.
• Behavior – Lethargy
was not seen in any neutered group. The sexually intact
cats showed greater aggression and fewer “demonstrations of
There are several techniques for accomplishing general
anesthesia in pediatric patients, but there are special
considerations that should receive the attention of the
An ovariohysterectomy eliminates many medical and
behavioral problems that a tubal ligation does not. In
fact, in many dogs, an OHE probably adds years to their
lives or at least provides them with a more comfortable,
less stressful life. The OHE does its part in pet
overpopulation, but you, as the owner of an individual dog,
should also view it as a way to increase the length and
quality of your pet’s life with you.