The word neuter comes from Latin, meaning of neither sex. To neuter is to remove all or part of an animal’s reproductive organ, and refers to animals of either sex. If one is speaking of males only, castration is the proper term, while to spay refers to the neutering of females. In horses, castration of the male horse is called gelding. Veterinarians refer to the practice as desexing. Humane societies, animal rescue organizations and animal shelters overwhelmingly promote neutering of pets, feeling that overpopulation of companion animals has resulted in a glut of unwanted animals. State regulations sometimes require adopted and rescued cats, kittens, dogs and puppies to be neutered before going to homes.