Before the 19th century, veterinarians used to carry out procedures without administering anesthesia to the pet patients under treatment. However, during the 1800s, they started adopting human anesthesia techniques, like using a bucket with an ether-soaked sponge to deliver the anesthesia. Such methods failed to ensure that pet patients were properly anesthetized. 

Veterinary anesthesia methods were revolutionized in the 20th century. This century witnessed the invention of specialized anesthesia machines, such as Gwathmey's machine and Trilux. These machines were developed for different species and animal sizes. Along with this, veterinary anesthesia inhalers also became popular. Masks were attached to the inhalers to fit different animal face shapes. 

Another major invention that changed veterinary anesthesia was intravenous (IV) catheters (thin tubes). These catheters, which were inserted into the animal veins during the mid-20th century, allowed...