Even if you buy a GP in perfect health from a pet store, it's going to encourage breeders to continue breeding. I know first hand the sad tales of abandoned and neglected guinea pigs that end up in shelters. Many have to be euthanized because the shelters can't handle the numbers. The SPCA in my State takes in 15,000 animals a year! (dogs, cats, rabbits, guinea pigs an others). If your local shelters don't have a lot of guinea pigs, be patient and take the time to find other sources of adoption.