Size Reference : Please see diagram
SMALL: Shitzhu, Daschund, Pomeranian, Maltese, Chihuahua, Pug, Yorkshire Terrier
MEDIUM: American Bully, French Bulldog, Corgi, Beagle, Golden Retriever, Poodle
LARGE: St. Bernard, English Mastiff, Alaskan Malamute, Bernese Mountain Dogs, Samoyed