Historically, hunter's companion was one of the most
important canine jobs. Most of the hunting (or sporting)
breeds were developed between the seventeenth and
nineteenth centuries for different types of game and terrain.
Terra, the Latin word for "earth," is the basis for the name
"terrier," given to a group of dogs bred to tunnel into the
earth, or "go to ground," to exterminate vermin. Most
terriers recognized today were developed in the British
Isles, some as long ago as the fifteenth century.
Mixed breeds--frequently referred to as "mongrels" or "mutts"--are the offspring of parents that are either mixed breeds or crossbreeds. (Crossbreeds are the
offspring of purebred parents of different breeds, such as an Irish setter mother and a Labrador retriever father.)