They're testicular implants for male dogs after neutering. They sound bazaar, but they actually do work. They look natural, they don't change the dog's self esteem, and minimize the trauma after surgery. It's a bit over the top, but this is an ongoing issue, particularly with men neutering their dogs.
Nudicals are prosthetic testicular implants for pets that have been neutered. They are designed to give the appearance that the pet still has its testicles after the surgery. Nudicals do not serve any medical purpose and are purely cosmetic.