The ASPCA defines a puppy mill as "a large-scale commercial dog breeding operation where profit is given priority over the well-being of the dogs." There is no legal definition of "puppy mill," and puppy mills aren't necessarily illegal. It is difficult to create laws that effectively crack down on puppy mills, but commercial breeding of dogs is regulated on the federal level and on the state level—but only in some states (see U.S. map of state dog breeding laws  [PDF])
The laws discussed below, which concern puppy mill-related standards and rules, are administrative laws—they are distinct from animal cruelty laws, which are criminal laws. (Commercial kennels that violate these kennel standards can be cited, similar to how restaurants that violate health codes can be cited.)
Typically, commercial kennel owners that violate the cruelty laws of a state are subject to criminal charges, but law enforcement cannot always obtain probable cause to enter a kennel to identify cruelty violations.
The Animal Welfare Act
The Animal Welfare Act (AWA), a federal law passed in 1966, regulates certain animal activities, including commercial dog and cat breeding. The AWA defines the minimum standards of care for dogs, cats and certain other species of animals bred for commercial resale, research, and exhibition. It also requires that certain commercial breeders be licensed and routinely inspected by the United States Department of Agriculture (USDA). However, the standards are far from what most people would consider to be humane . They are merely survival standards for dogs. For example, dogs in federally licensed breeding facilities can legally be kept in cages that are only six inches wider than the dog in each direction for their entire lives. Violations often go unpunished. Lack of enforcement by the USDA overall means thousands of dogs are left to suffer in inadequate and inhumane conditions year after year, even in federally licensed facilities.
There is good news, though: Until recently, only animal-breeding businesses considered "wholesale" operations—those that sell animals to brokers or pet stores for resale—were subject to oversight by the USDA. The AWA did not apply to facilities that sell directly to the public, including the thousands that now do so via the Internet. The result was that in many cases, no one regulated or inspected these facilities. Thanks to pressure from the animal welfare community and the public, in September 2013 the USDA issued a change to AWA regulations to close this loophole once and for all—for the first time, so-called “Internet puppy mills” will now be subject to USDA inspections. The rule went into effect on November 18, 2013.
On August 15, 2014, the USDA issued a new federal rule regulating the importation of puppies from overseas, taking significant steps towards ensuring the United States is not importing sick puppies and supporting animal cruelty in puppy mills abroad. Instead, the new law will now require non-U.S. breeders to provide certification that each dog is in good health, has received all necessary vaccinations and is at least six months of age.
Even though the Animal Welfare Act (and the USDA’s enforcement of it) leaves a lot to be desired, authorizing federal inspectors to go behind previously closed kennel doors for the first time will go a long way in improving the lives of tens of thousands of breeding dogs in puppy mills throughout the United States.
The 2008 Farm Bill
With the evolution of Internet commerce, puppy mills have sprouted up all over the world to provide poorly bred puppies of every imaginable breed and "designer mixed breed" directly to the consumer. As a result, the U.S. market has seen an increase in imported dogs in bad health and/or possibly carrying diseases that could harm people and other animals. Because foreign puppy mills are not subject to U.S. regulations—such as the standards set forth in the Animal Welfare Act—it is likely that many of these dogs are bred and raised in extremely inhumane conditions.
The ASPCA and other animal welfare groups successfully fought for an amendment to the 2008 Farm Bill that prohibits the importation of puppies under six months of age for the purpose of resale. Six years later, in August 2014, the USDA adopted regulations implementing the law at national ports of entry.
States have the power to legislate higher standards of care for commercially bred animals beyond the bare minimums required by the federal Animal Welfare Act, and more than half of U.S. states have chosen to do so. Unfortunately, 21 states have no laws on the books regulating commercial dog breeders—and a number of states, including Kansas and Texas, that do require breeders to be licensed and inspected by the state only require commercial breeders to meet USDA standards of care.
Among the states that do regulate, each government defines various terms (such as “pet store,” “breeder,” “kennel” and “dealer”) differently. To fully understand how producers and sellers of puppies are regulated in each state, careful attention must be paid to each law's precise wording.
Pennsylvania currently has the most stringent standards of care in the country for commercial breeders, requiring them to provide dogs with twice the USDA-regulated cage space, constant access to an outdoor exercise run and annual veterinary exams. The Pennsylvania law also prohibits the use of wire flooring and stacking cages on top of one another, both of which are legally permissible under the federal law.
In addition to laws that set forth standards of care and require breeders to be licensed and inspected, a few states (Louisiana, Virginia, Oregon and Washington) have enacted laws that limit the number of dogs a breeder may keep. Approximately 20 states have laws dictating how old a puppy must be before he or she may be offered for sale or adoption. To learn how your state stacks up, see our guide to state laws concerning breeders, kennels and puppy mills  [PDF].
While there has been a dramatic increase in the number of states considering and enacting bills to regulate the commercial breeding industry, it is important to remember that these laws hinge on enforcement. Strong standards of care are meaningless if inspections are never conducted and violations go unpunished. Therefore, in addition to pushing for stronger state laws, it’s important to work with enforcing agencies to make sure laws are being enforced.
Laws to Protect Consumers
If you buy a puppy from a pet shop, you are not only supporting the cruel puppy mill industry, but you also run the risk of taking home a sick animal. Puppies sold in pet stores may suffer from a range of illnesses and conditions, ranging from respiratory infections including pneumonia, to hereditary defects like hip dysplasia and severe allergies. Through our No Pet Store Puppies  campaign, the ASPCA urges people to pledge not to purchase anything, including pet supplies, in pet stores that sell puppies.
If you have purchased a pet store puppy who turned out to be sick, please tell us about your experience here . You also may have some legal recourse—as of August 2013, 21 states have enacted laws, commonly called "pet lemon laws," that make pet stores financially responsible for sick animals purchased from them. See a state-by-state list of pet lemon laws  and know your rights.
Join the ASPCA Advocacy Brigade!
By joining the ASPCA Advocacy Brigade, you will receive important alerts from us when we need your help to fight for laws against animals cruelty.