Should I neuter my dog or cat and
if so, at what age? “Neutering” means spaying a female or castrating a male.
Yes, but at what age, we cannot answer with certainty except to say that there are trade-offs. Neutering
later in life runs the risk of having to deal with pregnancy, too early and you run the risk of impacting normal growth and
development. Certainly the extent of the pet overpopulation problem in North America cannot be over-stressed. This
is due exclusively to unwanted pets and an unwanted pregnancy nearly always produces a litter of unwanted pets. If you
doubt this, go visit all the homeless animals at the Edmonton Humane Society. A visit here is the most compelling reason
to neuter your pet. Until a scientific
solution that factors in both the potential harm caused by neutering immature animals and the major reasons that support the
neutering of our pets can be found, we recommend the following:- Cats should be about 6 months of age at time of neutering.
- Dogs with an adult weight anticipated
to be less than 23kg / 50lbs should be neutered between 6 to 12 months of age.
- Dogs with an adult weight anticipated
to be more than 23 kg / 50lbs should be neutered between 12 to 18 months of age. Will neutering my pet before six months of age be detrimental to their health?
Maybe.
There is a growing body of evidence that refutes the commonly held notion that neutering prepubescent animals is harmless.
We now know that neutered animals have reduced metabolic rates, delayed growth plate closure, and their bodies select
fat over muscle mass when compared to intact (non-neutered) animals. We know that estrogen responsive urinary incontinence
in female dogs is a direct result of neutering. We also know that femoral head growth plate fractures is a disease of
young neutered male cats. There are two studies that identify neutering prior to maturity as a risk factor for cruciate
ligament rupture. Another study identified neutered animals as being at increased risk of developing bone tumours.
And yet another study identified a correlation between neutering early in life and a shortened life span in female Rottweilers.
Though by no means a license for obesity, but how can the slowed rate of metabolism and selection of fat over muscle mass
in neutered animals not contribute to the incidence of obesity in Canada's pets?
The two traditional reasons we
neuter our pets are for population control and the prevention of undesirable sexual behaviours. A neutered pet cannot
reproduce, period. Whether neutering males reduces generalized aggression though is not proven, though it certainly
will prevent males from fighting over a female in heat. Some will insist that there are “health benefits”
to neutering such as cancer prevention. This is only partly true. Neutered females do have significantly reduced
rates of mammary cancer and do not get ovarian or uterine cancer. However, the landmark 1968 study that highlights this
so called “health benefit” also showed that the rates for all other forms of cancer go up such that there is no
change in the overall incidence of cancer between neutered and intact female dogs. Obviously, neutered males do not
develop testicular cancer, though the majority of these tumours are benign. Unfortunately, no equivalent study for males
like the 1968 study of female dogs exists, though we do know that there is no measurable difference in prostatic cancer between
intact and neutered male dogs. Other purported “health benefits” include the prevention of pyometra (a life
threatening infection of the uterus) which is true, however the risk of pyometra is virtually zero until after the second
heat cycle.
