Spaying or neutering your dog or cat is an important part of being a responsible pet owner. It not only helps with population control but also has significant health benefits for your pet. For example, spaying your female dog before she goes into heat greatly reduces her chance of developing mammary cancer later in life. There are similar benefits for male dogs as neutering lowers their chance of developing some types of cancer.
There are behavioral benefits from spaying and neutering as well. For example, neutered male dogs are more likely to stay home. Dominant pets, or those with aggressive tendencies, can sometimes become more trainable when spayed or neutered.