When was the Elizabethan collar invented?

Answer 1

If you are referencing the fashion trend from the Elizabethan Era in European history, the trend caught on in the late 16th century when it was considered a "more seductive" look for women because garments revealed a portion of the neck.

The cone-shaped collars worn by animals around their necks after surgery are also called Elizabethan collars, or more recently E-collars. They have been in use since the mid-20th century as an effective method of preventing the animal from licking or chewing out surgery stitches or medicated skin areas. Electronic E-collars for training have been around since the 1950's.