1) Size matters! Puppies, especially mutts can grow up to the expected size. Even shelters and reputable humane societies have been known to underestimate the size of a dog by incorrectly guessing on the mutts mixed breeds. By adopting an adult dog there will be no surprises on size since the dog is adopted at full size.
2) Shelters and humane societies are full. Puppies are easy to find homes for, everyone wants a cute cuddly puppy. It is the adult dogs that are euthanized by the thousands every year while families fund puppy mills and private breeders by buying designer puppies that run upwards of thousands of dollars. Websites like petfinder.com allow you to search for dogs by age making it easy to find an adult dog in your area. Your local humane society will also have a selection of adult dogs.
3) No house training! Most adult dogs up for adoption at shelters and humane societies are already house trained for you. Potty training is the number one reason that most people do not want to own a puppy, but all that can be avoided by adopting an adult dog.
4) Less exercise and calmer personalities. Most adult dogs have grown beyond the excessive hyperness of puppyhood and have less need for exercise. Adult dogs are great for families with children or older couples that do not have enough energy to take care of a puppy. An adult dog is also great for individuals or couples that work full time. Since an older dog requires less exercise they usually will not mind being kenneled for a few hours a day as long as when you are together they get to play and cuddle with you.
5) No need to spay or neuter an adult dog. Since shelters, rescues, and humane societies spay and neuter every dog that is not already spayed or neutered before putting them up for adoption you will have one less responsibility. A spay or neuter can cost hundreds of dollars and requires follow-up medicine and lots of TLC for the dog.
6) Love and appreciation. I hear stories everyday about how adult dogs seem to understand that you have “saved” them from being euthanized. A rescued adult dog tends to show a type of appreciation that is never found in puppies that were never re-homed. This attitude is especially apparent in dogs that were previously abused. There is a special bond that develops between a rescued adult dog and the dogs owner.