Guinea pigs are widely considered to be good pets. They are generally easy to care for, although they do require frequent cage cleaning and companionship. If handled early in their life by caring owners, they become very amenable to being picked up and carried about, even by younger children. They are considered by many to be very cute and are very verbal (they squeak) in contact with humans. Guinea pigs who become familiar with their human seem to consider them part of their herd, and become distraught when separated for long periods.

Domesticated guinea pigs come in many breeds which have been developed since their arrival in Europe and North America. These varieties vary widely in hair and color composition.

All over the world there are Cavy Clubs and Associations dedicated to the showing and breeding of guinea pigs. The American Cavy Breeders Association is the governing body in the United States. In Canada, the Ontario Cavy Club is the most prominent club. Each club publishes its own Standard of Perfection and determines which breeds are eligible for showing.