How to Spot Puppy Mills. Identifying a puppy mill can be difficult. These organizations rarely interact with the public. Puppy mills typically sell their puppies inexpensively to pet stores that then resell them to the public. Responsible breeders never sell their dogs through or to pet stores, so you are virtually guaranteed that pet store dogs are produced by commercial breeders, backyard breeders or puppy mills, none of whom are likely to know or at least use responsible breeding practices. Some dogs have traits that alert you to the fact that it is or at least maybe, from a puppy mill. Puppy mill dogs are more likely to be unhealthy, and may be malnourished or suffer from chronic illness. Puppy mill dogs are also the most likely to exhibit behavioral problems, like continuously circling when in their cage, or have unstable temperaments. Puppies that are shy or fearful, thin or small for their age, or lethargic, may have been bred in a puppy mill but in any event, typically don't make a good choice for a pet. "Rescuing" Puppy Mill Dogs. Many rescue groups and other organizations work tirelessly to close down puppy mills and find good homes for the dogs 'rescued' from these conditions. Be aware that when you look at dogs from rescue groups, shelters, and humane societies, you may be looking at a puppy mill dog. Some people prefer to 'rescue' these dogs instead of buying an expensive purebred dog from a responsible breeder. Some people feel that it's more fulfilling to give a puppy mill dog a good home rather than perpetuate intentional breeding programs that produce expensive dogs when there are already more dogs than there are homes for them. There's nothing wrong with giving a home to a disadvantaged puppy mill dog. If you feel the plight of these dogs tugging at your heartstrings and think you'll find extra fulfillment by providing a home for these dogs, it might be worthwhile to consider getting a puppy mill dog from a rescue group or animal welfare organization. But if you do decide to share your home with a puppy mill dog, be aware that it may have special needs. It may develop health-related problems that require expensive medical treatment; or it may have behavioral or temperament problems that require extensive training that, even with the training, may not be able to be resolved. If you're not prepared to deal with these potential challenges, you should consider looking for a dog from a responsible breeding program with health-certified parents that you can verify have sound temperaments.