Castrator? 19 inches Veterinary instruments Stainless Steel Castration Clamp For Animals Sheep, Goats and Pig Castration Pliers,,,,,crushes the spermatic cord and stops the blood supply to the testes. Without this blood supply, the testicles atrophy (shrivel up) but the scrotum remains intact. It is a bloodless technique and less painful than surgical castration.