What Are Puppy Mills and Why Are They Bad?

headshot of a Lhasa apso dog

You visit a pet store or website, find the perfect puppy, and within minutes you've got your new best friend. Just because it's easy doesn’t mean it's a good idea. That's because most puppies for sale in pet stores and online are born and raised in factory-like, inhumane settings called puppy mills, where people see animals as a cash commodity rather than the way you do — as valued living beings deserving of homes that foster health and happiness.

Because puppy mill pets are raised in deplorable conditions with little human interaction, they run the risk of having significant behavioral issues that might not be apparent to the buyer until the new pet is brought home. In addition, puppies for sale from mills have a high chance of suffering from physical health issues due to malnourishment and poor health care.

Even though more and more people are taking a stand against them, the U.S. still has thousands of licensed and unlicensed puppy mills. So what are puppy mills and why are they bad? Here's what to know so that together we can take a stand against puppy mills and make them a thing of the past.

What are puppy mills?

A puppy mill is a commercial dog-breeding operation that values profit and maximum production over the health and welfare of the animals. In puppy mills, dogs live in tiny, crowded cages, which are often the minimum legal size allowed (only 6 inches larger than the dog on all sides), and female dogs are bred as frequently as possible to produce as many puppies as possible for the pet trade. 

Common alternative names for puppy mills include pet mills, commercial breeding facilities, commercial dog breeder, backyard breeders, or factory farms. But the fact is that no puppy mill will advertise the reality of its business. Instead, puppy mills attempt to pass themselves off as reputable, caring, and responsible breeders. Because puppy mill laws vary from state to state and city to city, it's important to check state and local legislation to learn what laws regulate breeders in your area.

Furthermore, many people don't realize that when they buy a dog from a pet store, that dog most likely came from a puppy mill. Pet stores that sell dogs from puppy mills don't usually disclose the origins of the dogs but instead use marketing jargon like “USDA-licensed” or “raised by a professional breeder.” Here's an important thing to remember: The federal Animal Welfare Act does not consider humane standards for animals' quality of life. For example, it is legal and common practice to keep dogs in small cages for their entire lives.

The history of puppy mills

The first puppy mills, opened by Midwest farmers in the post-World War II era, were an attempt to recover from widespread crop failure. Backed by the USDA as an easy and quick way to earn money, farmers turned their attention away from their fields and instead began loading dogs into chicken coops and selling them to retail outlets with pet departments.

As the demand for purebred dogs grew, puppy mills began to grow larger. And just like it is today, the puppy mill dogs of the 1940s were housed in crates, exposed to the elements, and left with almost no human interaction or veterinary care. And unfortunately the Animal Welfare Act that went into effect August 24, 1966, did little to change history for the better.

Puppy mills turn back the clock on community no-kill initiatives, as well as the work Best Friends Animal Society and our partner organizations are doing to ensure that all homeless pets find homes. But there is hope. By stopping puppy mill sales and encouraging adoption, together we can put an end to this cruel industry once and for all.

Why do puppy mills still exist?

Puppy mills have been inhumanely breeding and selling dogs for decades. Although the federal government regulates most breeders who sell puppies online and to pet stores, the minimal standards imposed on breeders don't promote ethical breeding or ensure healthy puppies; they only require the bare minimum of care. For example, it's legal for licensed breeders to own 1,000 or more dogs, to deprive them of socialization and exercise, and to confine them to wire cages for their entire lives without ever being taken out for walks or standing on solid ground.

So why do we continue to manufacture dogs in mills when so many dogs are losing their lives every day because they can't find homes? The answer, of course, is profit. And those who typically make the largest profit are the retailers who buy puppies for sale at a low cost and then resell them after a high markup.

Where are puppy mill dogs sold?

Unlike pets for adoption, puppy mill pets are often sold online or shipped to pet stores, where unsuspecting buyers are not informed of the conditions under which they were bred.

Pet stores

Nearly all pet stores that sell purposely bred puppies are supplied by mills. This can cause heartache and expense for those who purchase them with the mistaken belief that they were buying a healthy pet from the best possible source. So this is not just an animal welfare issue; it’s a consumer protection issue, too. 

More and more communities are banning the sale of mill-bred pets in stores. However, many Americans are still unaware of the connection between pet stores and puppy mills.


Just like pet stores, most websites that sell dogs are selling mill-bred pets. Most of these sites market the puppies as well-bred and lovingly raised. No matter how convincing a website is, though, never buy a pet online. 

Unscrupulous puppy sellers exploit the opportunity to hide behind attractive websites and slick catalogs that feature stock photos of adorable puppies frolicking in fields or napping in wicker baskets. Consumers who receive puppies shipped to them never see the true conditions of the breeding facilities they came from. They also have no way of knowing whether the puppy they purchase will be healthy or anything like what they thought they were buying, thus elevating the risk of consumer fraud. 

Classified ads

For decades, the newspaper classified ads were the first place that puppy buyers go to look for a new pet. Now, commercial breeders have adapted this marketing tactic by placing classified ads on popular online platforms. Please beware of any ads that list several breeds for sale. And if the breeder won't let you see where the dogs and puppies live, please don't buy the puppy.

Dog breeders: Can they be trusted?

Best Friends is committed to saving homeless pets. And until our mission has been achieved and every pet has a loving home, we urge everyone to adopt their next pet from a shelter or rescue organization.

Best Friends understands and recognizes that there are responsible puppy breeders who adhere to high standards of care for their animals. However, many commercial dog breeders who are breeding dogs to sell wholesale to pet stores and distributors follow only the minimum required USDA standards of care, which do nothing to protect dogs and to promote responsible, quality breeding.

The fact is that a responsible breeder would never sell to a pet store. This is a basic tenet in every reputable breeder’s code of ethics, including those of the parent breed clubs of the American Kennel Club (AKC). And even if breeders were inclined to sell AKC dogs to pet stores, the high cost of breeding responsibly means that a pet store could never afford to buy AKC puppies from a reputable breeder because the profit margin would be significantly less than it is when they buy from mills or brokers.

Best Friends' position on dog breeding

Health problems associated with puppy mill dogs

Dogs from puppy mills often suffer from a variety of health problems and genetic issues caused by poor living conditions and inbreeding. Tragically, when the cost of caring for a sick puppy becomes more than the buyer can manage, it is not uncommon for that puppy to be surrendered to an overcrowded, taxpayer-subsidized shelter.

Some of the most common health conditions that affect dogs from puppy mills include:

  • Heart disease
  • Kidney disease
  • Musculoskeletal disorders
  • Deafness
  • Respiratory disorders
  • Endocrine disorders, including diabetes and hyperthyroidism
  • Vision and eye problems

Other diseases and health problems can include:

  • Parvovirus
  • Distemper
  • Kennel cough
  • Pneumonia
  • Mange
  • Fleas and ticks
  • Intestinal parasites
  • Heartworm
  • Bowel disease

Behavioral issues associated with puppy mill dogs

Puppy mill dogs spend most of their lives in fear and without proper socialization with humans or other dogs. The first months of a dog's life are a critical time for behavior and personality development. But because puppies in mills are taken from their mothers at 6 weeks old, they are denied the necessary maternal interaction they need to feel safe and secure in the world.

Dr. Frank McMillan, a veterinarian who was formerly the director of well-being studies at Best Friends, has found that puppy mill dogs are born and raised into extremely stressful environments. In fact, they endure so much stress that their psychological functioning is severely impaired. They have difficulty interacting with people, make limited eye contact, have poor attention spans, and can have trouble socializing with other dogs. Those challenges can plague dogs for their entire lives.

Helping puppy mill dogs adapt to home life

Best Friends Animal Society's puppy mill initiatives

Through Best Friends Animal Society's puppy mill initiatives, we are working to:

  • Convince pet stores to offer homeless pets for adoption instead of selling mill-bred pets
  • Educate consumers about puppy mills
  • Create and lobby for humane legislation

Best Friends is helping people throughout the U.S. put an end to puppy mills by helping them pass ordinances that ban commercially bred puppies for sale in pet stores. By cutting off the supply of milled puppies being imported into a community, people across the country are addressing the puppy mill problem from the retail end, while increasing adoption opportunities for pets in local shelters.

At Best Friends, we emphasize the importance of adopting pets over buying them and are working to create a cultural shift in the way we think about companion animals and how we choose to bring them into our homes. Adoption is becoming much more common as legislators recognize the need to pass better regulations for dog breeders and retailers. And there is more awareness than ever about the harsh realities of puppy mills. As people share their knowledge and take action in their own communities, we are steadily moving the needle in a more compassionate direction.

Together, we’re making an impact and saving lives. And animal lovers like you can join us and help bring about a time when every dog can feel safe, happy, and loved.

How to fight puppy mills

Although we’ve made incredible progress, amazing dogs of all types are still losing their lives in U.S. shelters every day simply because they don’t have safe places to call home. And one of the easiest ways you can help is by choosing to adopt instead of purchase a pet.

When you adopt, you’re not only refusing to support puppy mills, but you’re also saving a life and giving a deserving animal in need a second chance. If you’re looking for a particular breed of dog, no worries. Shelters and rescue groups have dogs of all breeds, ages, colors, and sizes.

Here are a few other ways you can fight puppy mills:

  • Spread the word: Tell your friends, family, and other people about puppy mills, and encourage them to adopt their next furry friend.
  • Donate to Best Friends Animal Society.
  • Learn more about the puppy mill problem, and get the tools and resources you need to help fight puppy mills.

What it comes down to is this: The puppy mill problem belongs to all of us and so does the solution. The ability to put this cruel industry in the past is in our collective hands. 

We have the power to set positive examples through our consumer decisions. We have the power to teach compassion for animals to our kids and each other. We have the power to create changes for the better. We have the power to save lives. 

Working together, we can reach a time when puppies will no longer be mass-produced, when adoption will be the first choice for those looking to bring a pet into the family, and when there will be no more homeless pets. We're on the right track.

Together, we can Save Them All.

Speak up against puppy mills