What does "fixed" mean regarding pet ownership?

In the context of pet ownership, "fixed" refers specifically to animals that have been spayed or neutered. This surgical procedure is performed to prevent dogs and cats from reproducing. Spaying involves removing the reproductive organs of female animals, while neutering refers to the removal of the testicles in male animals. The term "fixed" signifies that the pet can no longer contribute to pet overpopulation, which is a significant concern in communities across the world.

Addressing the other options, animals trained for specific tasks do not relate to the concept of being "fixed" in any context other than performance training. Animals left in the wild not only fail to address the idea of a domesticated pet but also imply a lack of ownership or care. Lastly, animals trained to be aggressive pertain to behavioral conditioning and do not involve any reproductive considerations. Thus, the concept of being "fixed" is solely associated with spaying or neutering procedures.