Your veterinarian should initiate a discussion about spaying or neutering at the time of your first appointment, months in advance of the actual surgery. If he or she doesn't, then inquire. When the puppy is very young is a good time to start thinking about whether you want to spay or neuter your pet for preventative health care, birth control and to avoid some potentially undesirable behavior.

Many breeders offer pet quality puppies for sale with the stipulation that the dogs be neutered or spayed when they reach the appropriate age. This is the breeder's way of insuring breed improvement, by only allowing high-quality dogs to reproduce. You, of course, think your puppy is absolutely perfect. And it is - for you, and as a pet, but perhaps not as a model for future members of its breed.

Possibly the best reason to have your female spayed while she is young (most veterinarians recommend six months of age) is for its health benefit. Mammary gland cancer is much more common, in an unspayed (intact) female. If your puppy is spayed before her first heat (at six months, for example), her risk of developing breast tumors is substantially reduced. The odds are still in her favor, though diminished, if she is spayed after her first heat. But if you wait until she reaches maturity, say after her second or third heat, the operation will not reduce her risk of breast cancer. This is why it is important to have her spayed early in life.

Other reasons? The surgery itself, complete removal of the uterus and both ovaries, is ordinarily quicker and less hemorrhagic in immature females, so the risk of complications is reduced. Owners are spared the stress of having to confine the female who, when she comes into season, sends out enticing messages to male dogs in the vicinity. Furthermore, because the reproductive organs are gone, spaying eliminates the possibility of unwanted pregnancy as well as the regular heat period when dogs leave blood-tinged stains on carpets and furniture. Lastly, the potential infections, cancers and other problems involving the uterus and/or ovaries are eliminated along with these organs. Diseases of the male reproductive organs related to the presence of male hormones are not unknown, either. Although neutering represents an advantage as far as prevention is concerned, this is not usually the primary reason owners have their dogs castrated.

Most people want their dog to be neutered because they think it helps make him a better pet. This may be true, for the following reasons: Intact male dogs can act aggressively toward other dogs and people because they are trying to protect and control their territory. In the male mind, "territory" may be your property, its toys, females in heat, a bowl of food and so on. This type of behavior is unacceptable to most people and may be strongly influenced by the dog's male hormones. Neutering a dog with aggressive tendencies at an early age may reduce these problems. Castration is also recommended for aggressive older dogs, although its chance for success is less certain.

A neutered dog has less temptation to roam, too, as well as fight. He probably won't embarrass you at important dinner parties by seeking romance with your company's legs. And just as important, he won't contribute to the already burgeoning population of homeless puppies, something we should all be ashamed of.