Allen Christian Smith, The Raising and Care of Guinea Pigs
“ If you expect to raise Cavies for commercial purposes the English is the kind that should pay you best. They are easier to take care of than the long-haired varieties. For laboratories, experimental purposes, etc., it is the smooth-haired Cavy that is in most demand. If you are a Guinea Pig fancier or are raising them for pet purposes it is merely a matter of taste and choice. The long-haired ones are usually more expensive and sell for more, as they are scarcer and are generally sold for pet and fancy purposes. ”
