Adopting a dog prevents the support of puppy mills and backyard breeders, which often keep dogs in cruel conditions and force them to breed frequently.

Shelters and rescue groups have a variety of healthy, well-behaved dogs of all ages.  Many shelter dogs are already house-trained and used to living with families.  Many shelter cats are already litter-box-trained.

Adopting a dog or cat can be less expensive because the animal is already up-to-date on vaccinations and has already been spayed or neutered.  Some are already micro-chipped!  The initial cost of having a pet is often the immediate vet costs associated with ownership.

Adopting a pet also allows you to choose from a wide range of animals of different ages and personalities. Many shelters will allow you to bring the family and current pets to their "meet-and-great" area to see how they get along together.  This is also called "testing" to see how animals react to other species and sizes of animals as well as children.