Never buy an animal. Encourage friends and family to do the same. Purebred breeds can be found at shelters and rescues, you just have to do some research if you care enough.
Most dogs and cats are only kept about 72 hours due to space restrictions and the high surplus of animals being surrendered to the shelter.
Help save a life by choosing to adopt from a shelter or rescue; and not just dogs and cats, you’ll also find other animals like rodents, rabbits, exotics — it’s always best to check with one or both, than resort to a breeder or pet store.
Unless a shelter operates as a no-kill (very few do and we need much more of) many shelters have no choice but to kill perfectly healthy and adoptable would-be pets, which also includes puppies and kittens, they are not exempt.
Not all shelters euthanize humanely, there are many that still use gas chambers and the heart-stick method. These are both heinous methods and need to be banned; such barbaric cruelty should not exist in this day and age.