NEUTERING THE MALE DOG
Most male animals (stallions, bulls, boars, rams and tom cats) that are kept
for companionship, work, or food production are neutered (castrated) unless
they are intended to be used as breeding stock. This is a common practice to
prevent unacceptable sexual behavior, reduce aggressiveness, and prevent accidental
or indiscriminate breeding. However, many dog owners choose not to neuter their
male dogs, despite the benefits.
How does neutering affect behavior?
The behaviours that will be affected by castration are those that are under
the influence of male hormones (see below). A dog's temperament, training, personality
and ability to do "work" are a result of genetic factors as well as its upbringing,
not just its male hormones. Castration does not necessarily "calm"
an excitable dog, and unless a castrated male dog is overfed or under-exercised,
there is no reason for it to become fat and lazy.
What is castration?
Castration or neutering of male dogs is surgical removal of the testicles
(orchidectomy). The procedure involves a general anesthetic. An incision is
made just in front of the scrotal sac and both testicles removed, leaving the
sac intact. Vasectomies are not usually performed since it is both sterilization
and removal of the male hormones that provide the behavioral and medical benefits
Which of my dog's behavior problems can be expected to improve following
As mentioned, only those behaviours that are "driven" by male hormones, can
be reduced or eliminated by castration. Although the hormones are gone from
the system almost immediately following castration, male behaviours may diminish
over a few days or gradually over a few months.
Undesirable sexual behavior: Attraction to female dogs, roaming, mounting,
and masturbation can be reduced or eliminated by castration.
(a) For roaming there is reported moderate improvement in 70%
of dogs and a marked improvement in 40%. For mounting there is reported
to be a moderate improvement in 70% of dogs with marked improvement in 25%.
(b) In one study, castration led to reduced aggression toward other
dogs in the house in 1/3 of cases, towards people in the family in 30% of
cases, towards unfamiliar dogs in 20% of cases and towards unfamiliar people
in 10% of cases.
Urine Marking: Most adult male dogs lift their legs while urinating.
Instead of emptying their bladders completely, most male dogs retain some urine
to deposit on other vertical objects that they pass. Some males have such a
strong desire to mark that they also mark indoors. Castration reduces marking
in 80% of dogs with a marked improvement in 40%.
Aggression: Neutering will prevent reproduction and passing on of any
genetic tendency towards aggression. Castration may also reduce or eliminate
some forms of aggression (i.e. those that are influenced by male hormones).
Are there any additional benefits to castration?
Medical benefits: Castration eliminates the possibility of testicular
cancer and greatly reduces the chance of prostatic disease, two extremely common
and serious problems of older male dogs. Many older dogs will develop prostate
disease or testicular tumors if they survive to an old enough age. Castration
can also reduce the risk of perianal tumors and perineal hernias.
Population control: Perhaps the most important issue is that millions
of dogs are destroyed annually at animal shelters across Europe and North America.
Neutering males is just as important as spaying females when it comes to population
Are there any risks?
Nowadays, with the broad selection of anesthetic. agents and state of the
art monitoring, it is extremely rare for there to be anesthetic. or surgical
complications during a canine castration.
Most young and healthy animals recover without incident. Often, the biggest
concern is not the surgery and anesthesia, but the recovery, since we need to
ensure that the dog does not lick excessively at its incision line until it
is fully healed. Careful monitoring and specific management for example, the
use of a protective collar, known as an Elizabethan collar, will be required
if excessive licking is observed following castration.
When castration is being considered for an older dog, the benefits must be
weighed against any risks associated with the anesthetic. and surgery. Since
castration surgery is seldom associated with any complications, it is the anesthetic.
that is the primary concern. If castration is being considered as a separate
procedure for a medical reason (prostatic enlargement, testicular tumors, perianal
tumors), then there is a significant benefit to the dog's health, comfort and
perhaps longevity, in having the castration performed. If the dog is exhibiting
any undesirable behaviours that might be improved by castration (roaming, masturbation,
mounting, inter-dog aggression, excessive sexual interest or marking), there
may also be a significant benefit to be gained from castration. Although not
infallible, a physical examination and any additional screening that your veterinary
surgeon may feel is appropriate such as blood and urine tests or ECG/EKG can help
to evaluate the level of risk posed by the anesthetic. These tests can also
help the veterinarian determine which anesthetic. protocol would be safest for
your pet. Since many older pets require anesthesia for other procedures (e.g.
growth removal, preventive dentistry), the benefits can often be further increased,
and the number of anesthetic. procedures reduced by performing the castration
along with the other health maintenance procedures.
What age is best for preventive castration?
A number of studies have shown that castration is as effective at preventing
male associated behavior problems as it is at reducing them. This means that
whether the pet is castrated post-puberty (e.g. 1 year or older) or pre-puberty
(e.g. 2 months of age) the behavioral effects are likely to be the same. There
is, however, anecdotal evidence that dogs that are sexually experienced are
more likely to retain their sexual habits after castration, compared to those
dogs that have had little or no sexual experience prior to castration. Recently
it has been advocated that castration be performed at as young an age as is
practical, to ensure that it is done before the pet has a chance to breed. This
is most important in animal shelters since it allows them to ensure that every
dog adopted has already been castrated. To date, studies have shown that castration
is safe, and has no long term detrimental effects on health or behavior, regardless
of the age that it is performed. In some cases a puppy may be neutered as young
as 2 months of age. Reports from these studies suggest that the surgery is often
shorter and that recovery is quicker with less postoperative discomfort. However,
many people like to wait until the animal is older, waiting until all vaccinations
are complete before admitting the pet into the hospital for surgery. However,
if general anesthesia is needed prior to the vaccinations being completed for
any other reason (e.g. suturing a cut, removing quills) this could be an excellent
time to consider castration. In summary, there seems to be no behavioral or
medical benefit to waiting until a dog is "mature" to perform a castration.
My dog has retained testicles - what does this mean?
During fetal development or shortly after birth, the testicles will descend
into the scrotal sac. In some dogs the testicles may not descend fully. In many
cases this is believed to be a genetic tendency. These dogs are known as either
unilateral (one testicle) or bilateral (both testicles) cryptorchids. The testicle
may be retained in the abdomen or anywhere between the abdominal cavity and
the external sac. Retained testicles do not usually produce sperm, but they
will produce hormones, which can lead to any of the behavioral changes or medical
problems previously discussed. In fact, retained testicles may be more prone
to developing cancer. At the very least, it would be extremely difficult to
determine if a testicle which is located in the abdomen, begins to develop cancer,
since it cannot be palpated until it is greatly enlarged. All dogs with retained
testicles should be neutered for medical and behavioral reasons, and to ensure
that this genetic abnormality is not perpetuated.
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