File under "awkward moment."

File under "awkward moment."

A couple of weeks ago, Uno the Westminster-winning beagle appeared on "Good Day L.A." While the Best in Show beagle was tail-waggingly gregarious, a couple of hackles got raised between his human companion, Westminster commentator David Frei, and anchor Gillian Barberie.

Barberie voiced her support of the city's recently passed mandatory spay-neuter law, which requires puppies and kittens to be sterilized by 4 months old. In turn, Frei — who was in town with Uno to present a $2,500 check to the Concerned Dog Owners of California to support its legal challenge to the ordinance — ticked off all the health risks of performing those surgical procedures too early.

The two found common ground on the subject of subsidizing spay/neuter surgeries for those owners who cannot afford them, and moved on.

The argument, however, remains. At its heart is not so much the question of whether owners of cats and dogs should take them in for that ominous-sounding "gonadectomy," but rather when.

Thankfully, there is an objective lens through which to view this polarizing debate. In the December 2007 issue of the Journal of the American Veterinary Medical Association, veterinarian Peggy Root, an associate professor of small-animal reproduction at the College of Veterinary Medicine at the University of Minnesota in St. Paul, took a survey of all the sterilization-related research.

"Optimal age at which to spay and neuter dogs and cats has never been determined scientifically," says Root. "It is in the best interest of dogs and cats to ensure we're weighing all the benefits and detriments for such a common procedure."

The 11-page paper outlines the advantages of spay/neuter, starting with its benefit in curtailing animal overpopulation. Unaltered animals are more likely to be relinquished by owners, and they exhibit "sexually dimorphic behaviors" like mounting and urine-spraying.

Healthwise, there are a number of benefits to altering dogs and cats. In female dogs, spaying before the first heat all but eliminates the risk of mammary cancer, with intact dogs having seven times the risk of developing these malignant tumors than their spayed counterparts.

Noncancerous prostatic disease is a given in older unneutered male dogs; they are also logically at risk for testicular cancer, though the incidence is low. And unspayed females can develop pyometra, a life-threatening infection of the uterus.

And let's not forget the biggie: Spayed and neutered animals live longer, though that may have more to do with the fact that owners who are responsible enough to alter their animals are also more likely to give them regular vet care and not allow them to get into harm's way by roaming.

Then there is the other side of the balance sheet. Though it seems counterintuitive, neutered dogs are at greater risk for prostatic cancer. Altered animals of either sex have higher levels of bladder cancer, osteosarcoma (bone cancer) and hemangiosarcoma, especially in breeds where there is a genetic predisposition. Ditto for ruptured cruciate ligaments, obesity, diabetes and hypothyroidism.

And then there are the studies that conflict with each other. Root sites one in which cognitive dysfunction was slowed in unneutered dogs, then another in which intact beagles had more DNA-damaged brain neurons than unaltered ones. The jury is out, apparently, over whether having testicles makes you dumber.

In weighing all the pros and cons, Root arrives at some intelligent guidelines: First, animals in shelters must be regarded as a "population," and not as individuals, and the societal benefit of spaying and neutering them before adoption — even at a very early age — outweighs any health risks.

Next, male cats, who in their non-snipped state can be unpleasant, if not dangerous, to live with, need to be neutered "prior to puberty," Root recommends.

That leaves female kitties and male and female dogs who live in secure, presumably responsible homes. Rather than treat them with the same broad brush reserved for shelter animals, Root encourages owners to weigh risk factors, including the animal's breed and genetic predisposition, with their veterinarian. That may mean 9 months for a female golden retriever who comes from lines that do not experience their first heat until one year, or 18 months for a male Rottweiler who comes from a family of dogs predisposed to bone cancer.

No matter what number you and your vet arrive at, make sure it is predicated on good science and common sense — not political drumbeats created to address that amorphous "greater good."