1. YOU'LL SAVE A LIFE (3-4 million dogs and cats are euthanized in shelters every year)
2. YOU'LL ADOPT A HEALTHY PET (purebreds are often inbred, causing heath problems)
3. YOU'LL SAVE MONEY (it costs much less to adopt from a shelter)
4. YOU'LL FEEL BETTER (not only will your new pet give you lots of love, research has shown that pets improve our physical and mental well-being as well)
5. YOU WON'T BE SUPPORTING PUPPY MILLS (Puppy Mills are "factory style" dog-breeding facilities that put profit above the welfare of dogs. Most dogs raised in puppy mills are housed in shockingly poor conditions with improper medical care, and the parents of the puppies are kept in cages to be bred over and over for years, without human companionship and with little hope of ever joining a family. And after they're no longer profitable, breeding dogs are simply discarded—either killed, abandoned or sold at auction. Puppies from puppy mills are often sold to unsuspecting consumers in pet stores)
Information from the Humane Society