Good Deal from the AKC
Now something of a disclaimer. I have a purebred (my Golden, which I inherited from a friend), but I also have three mutts - all of them strays - and it goes without saying that I love them equally. I'd never judge anyone who bought a purebred, but I have a strong inclination to rescues and shelter animals, most of which are mixed breeds (though shelters always have purebreds; during a recent visit to the Miami-Dade County shelter, I saw a Dalmatian, a couple of cocker spaniels, a beagle, a chocolate Lab, and all kinds of purebred cats).
Pet overpopulation is a tragedy, and a shame on the human race. When we domesticated animals, we made a deal with them: You protect and work for us, we'll take care of you. When it comes to overpopulation, we have not kept up our end of the bargain. In this country alone, an estimated 9 million euthanized dogs and cats pay the price for that every year. It's morally wrong.
The only way to reduce that number is to increase spay/neuter rates, shut down the puppy mills, and increase shelter/rescue adoptions. Please consider it when you're looking for your next pet.