When performing feline castrations, I use a neuter shield to help prevent stray hair from getting attached to the cord. To make the shield, I cut part of an Elizabethan collar into an 8-cm-diameter circle, pierce a small hole in the center, and make a single cut from the circle's edge to the hole. I sterilize the shield in a cold sterilization solution. I place the shield between the cat's scrotum and testicles with the cord passing through the center hole. The shield keeps stray hair from getting caught in the knot and helps maintain a sterile field.
Dr. Paul Fahlman