What is a common consequence of neglecting to spay or neuter a pet?

The issue of spaying or neutering pets is crucial in managing the pet population and preventing various problems associated with unaltered animals. One of the most significant consequences of neglecting to spay or neuter a pet is the increase in unwanted litters. When pets are not altered, they are able to reproduce, leading to more puppies or kittens than can be adequately cared for. This situation contributes to overpopulation in shelters and can result in the abandonment of animals or euthanasia for those that do not find homes.

In contrast, altering pets typically prevents these unnecessary litters and helps control the overall population, thereby reducing the strain on animal shelters and improving the lives of many animals that need homes. The other options do not accurately reflect the broader implications of not spaying or neutering, focusing instead on individual behavioral or health outcomes.