What is the horn worn on a dog's neck?

The horn worn on a dog's neck is an Elizabethan collar, also called a protective collar or a circle of shame. Elizabethan rings are shaped like a trumpet and are specially designed to prevent dogs from licking or scratching wounds. When a dog wears an Elizabethan collar, the dog's activity space has certain limitations, which can restrain the dog's actions very well.