Page 27 - Chow Life - Winter 2017

in the latter group is tagged at 100 One study showed an increased the article by Zink is pyometra. This
percent. Bitches spayed before the first incidence with early spaying (before occurs in unspayed bitches and is a
heat have an odds ratio of 0.005, those 3 months of age). Those researchers potentially life-threatening condition.
with one heat 0.08, and those with two concluded that sterilization is Howe says the incidence has been
or more heats, 0.26. best done after 3 months of age to reported to be as high as 66 percent in
These odds ratios are often minimize this condition. bitches over 9 years of age.
reported as absolute risks and used as Another paper, in contrast, suggests There is good data on this topic, as
percentages (e.g., as 26 percent risk of that risk of urinary incontinence is only 7 percent of bitches are spayed in
getting cancer). The true numbers are lower in early spayed bitches than Scandinavian countries. In a Swedish
lower than that. those spayed after the first estrus, but pet insurance study, 25 percent of the
Does neutering before a year of age the clinical signs of those affected insured dog population developed
boost the incidence of bone cancer? tend to be more pronounced. Those pyometra by 10 years of age. This
According to Zink, a study of 3,218 authors also state that because puts the incidence of this condition
most bitches far higher than rupture of the
respond well cruciate ligament and development
to medication, of hypothyroidism. It can also be
“The problem with much of the it is of minor prevented by ovariohysterectomy.

available information is it is based on importance.
Zink proposes
personal opinion.” that infectious Making a Decision
diseases are The decision on when to sterilize
more common must be based on a full understanding
dogs showed that those neutered in dogs spayed or neutered at 24 of the scientific literature. As new
before a year of age had a significantly weeks or less compared to those studies are performed on early-age
increased chance of developing it. undergoing surgery at an older age. versus traditional sterilization, we
may see recommendations change.
The Cooley study quoted by Zink This fact was concluded in a study, However, until these studies are
was interpreted differently by Howe. but Zink failed to include another performed, any assumptions are
She pointed out that the study was important fact: The dogs were from anecdotal.
on 683 Rottweilers. This breed was a shelter environment where the
selected because of its high risk of incidence of parvoviral infection was Also, the balance of health risks and
bone sarcoma. In all, 12.6 percent of high. benefits of sterilization differs for each
the dogs developed bone cancer, and The effect of the anesthesia and dog based on gender, age, and breed.
that male and female dogs sterilized stress of the surgery was also not These must be taken into the decision
before 1 year of age did have a higher considered. There was no comparison of when (or if) to spay and neuter.
risk than those that were sexually to age-matched controls that did not Across-the-board recommendations
intact. Time of sterilization was not undergo surgery. The researchers are not possible.
studied, but their conclusion is that suggested that the incidence of
there is an increased risk of bone parvovirus in the dogs reflects an
cancer with sterilization before 1 year increased susceptibility of dogs of that Dr. Jeff Grognet is a veterinarian
of age. age to that specific infection rather with a practice in British Columbia,
Cancer of the prostate gland than an effect of the age they were Canada, and is a regular AKC
occurs in both intact and neutered sterilized. FAMILY DOG contributor.
male dogs, and Zink suggests that Zink suggests that spayed and
neutering provides no benefit in neutered dogs are more likely to
preventing this disease. Howe agrees, develop hypothyroidism. Howe says This article first appeared in the
but she also points out that it is well this is true, but the overall incidence of October 2010 AKC Gazette and is
documented that castration helps hypothyroidism in dogs is 0.2 percent reprinted with permission. To read the
prevent other prostatic diseases such (some breeds may have a higher online Gazette, visit www.akc.org/pubs.
as benign prostatic hyperplasia, cystic or lower incidence). Discouraging
hyperplasia, prostatic cysts, and sterilization to prevent a disease
abscesses. with such a low incidence that has a
good response to supplementation
when other diseases have a much
Other Sterilization higher incidence (mammary cancer
Concerns and prostate problems) and a poorer
Urinary incontinence is seen more outcome does not make sense.
often in spayed than intact bitches. One disease not mentioned in
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