What Is A Puppy Mill?

And are they really so bad for dogs? 🤔

puppies in a cage

Have you ever been walking down the street and seen a cute little puppy in a pet store window and wanted to buy him? Those puppies are pretty adorable, but did you know that most of them come from puppy mills?

Puppy mills are large-scale breeders that breed dogs for profit at the expense of the puppies’ (and their moms’) wellbeing, and a lot of pet stores get their dogs from puppy mills.

The Dodo spoke to Dr. Michelle Burch, a veterinarian from Safe Hounds Pet Insurance, to find out everything you need to know about puppy mills.

What are puppy mills?

Puppy mills are organizations that breed dogs for profit, often at the expense of all the dogs in their care.

“A puppy mill is a facility that has an abundant number of dogs used for quick breeding,” Dr. Burch told The Dodo. Puppy mills also feature “lack of breed standards, lack of testing for diseases prone to the specific breed and poor living conditions,” she said.

“The health of breeding dogs is also disregarded to help improve profits from the sale of puppies,” Dr. Burch added.

Why are puppy mills bad?

A puppy mill’s goal is to breed as many dogs as possible to earn a profit, so they prioritize the breeding of dogs over their wellbeing.

In other words, a puppy mill puts profit above all else — meaning that dogs aren’t properly cared for and have to deal with disease and sometimes unbearable living conditions.

This leads to numerous health and behavioral problems for the puppies and their parents (who spend their lives being bred over and over to produce as many puppies as possible).

It also means if you buy a puppy who originally came from a puppy mill, you may end up dealing with a lot of challenges you wouldn’t normally face as a new pet owner.

Overcrowding and poor treatment

Because the goal of puppy mills is to earn a profit, they crowd as many dogs as possible into small spaces, which leads to problems for the dogs.

“The overcrowding will result in owners of puppy mills stacking wire cages in small spaces which cannot be adequately cleaned of urine and feces,” Dr. Burch said. “Accumulation of waste results in skin infections, respiratory disease and systemic infection to the breeding dogs.”

Because there are so many dogs in small wire cages, they often have joint and muscle damage from being cramped in small spaces, Dr. Burch said.

And in most cases, these sick dogs are often not provided adequate veterinary care because of the cost.

Health problems

Unfortunately, many people buy that adorable puppy they fell in love with at the store only to find out when they get home that he’s infected with a disease he caught at the puppy mill.

“Puppy mill dogs tend to come home with infectious diseases, including giardia, parvovirus, distemper, upper respiratory infections, kennel cough, pneumonia, mange, fleas, ticks, intestinal parasites, heartworm or chronic diarrhea,” Dr. Burch explained.

These diseases can sometimes have fatal results in young puppies, and even in a best-case scenario, they mean a lot of unexpected vet bills and stress.

And some of these health problems can become problems for you and your family as well — there are some illnesses and health issues that can transfer from dogs to people, such as intestinal parasites, fleas and ticks.

Puppy mill breeders also often don’t remove sick dogs from the breeding pool. This means that puppy mill dogs are more likely to have congenital and hereditary conditions that are passed down from dogs who weren’t screened for diseases before being used for breeding.

“These conditions include epilepsy, heart disease, kidney disease, musculoskeletal disorders, blood disorders, deafness, eye problems and respiratory disease,” Dr. Burch said.

Even if your puppy looks healthy when you get him, many of these genetic conditions might not show up until much later when your puppy grows up.

These genetic conditions can be extremely expensive to treat and often require thousands of dollars in treatments like surgeries, physical therapy and medication.

The worst part is that when puppies are born with a genetic issue that is immediately obvious, they’re often killed.

“Puppies who are born sick, or with congenital abnormalities, are also killed almost immediately,” Dr. Burch said. “These puppies will not profit the puppy mill, and [the mill] will not seek veterinary care for these dogs.”

Socialization and behavioral problems

In addition to health issues, many puppy mill dogs have socialization and behavioral problems because of their stressful start in life.

“Puppies are removed from littermates and their mother at 6 weeks of age during the critical socialization period of their life,” Dr. Burch said. “Removing these puppies at such a young age can result in extreme shyness, aggression, fear and anxiety.”

Puppies should stay with their mothers until they’re at least 8 weeks old. The main reason for this is feeding — the mom’s milk has the nutrients a puppy needs to develop properly.

But puppies also learn socialization from their moms and littermates, such as how to communicate and play nicely with others. When puppies are taken from their mothers too early, they aren’t socialized properly and can develop lifelong issues with aggression, anxiety, fear, possessiveness and difficulty interacting with other dogs.

Adult dogs in puppy mills also develop behavioral problems from the neglect and lack of proper care as well, though most of them never have a chance to escape the puppy mill since they’re used for breeding instead of selling.

“Adult dogs develop behavioral disorders from the lack of socialization, environmental enrichment and basic daily needs,” Dr. Burch said.


Because the sole purpose of a puppy mill is to turn a profit, they breed dogs as often as they can, which is extremely unhealthy for the mother dogs.

“These dogs are given no chance to recover between litters, and their body is physically depleted due to lack of recovery,” Dr. Burch said.

And like the puppies who are born sick, female dogs who aren’t able to reproduce quickly enough are often euthanized because they aren’t profitable to the puppy mill, Dr. Burch said.

How can you tell if a dog came from a puppy mill?

There are a few ways to tell if a puppy came from a puppy mill.

An easy way to know if a dog came from a puppy mill is where he’s being sold (and the fact that he’s being “sold” at all). Basically all dogs sold at pet stores came from a puppy mill, unless the pet store is one that features only adoptable pets (which you’ll know because there will usually be a rescue’s name prominently displayed or an adoption volunteer from the rescue they work with on-site at the store).

You can also tell by the price — since puppy mills are designed to make a profit, their dogs are often sold for many hundreds or even thousands of dollars, while genuine dog rescues will usually only charge a nominal fee (of around $50 to $200) to cover the rescue’s basic costs.

“Puppies from a puppy mill are almost always sold through a broker or a middleman,” Dr. Burch said. “The puppy mill itself will very rarely sell its puppies. These puppies tend to be sold through pet shops, but also through the internet, newspaper ads, swap meets or flea markets.”

Another way you can tell is if the puppy is under 8 weeks old. Many puppies from puppy mills will be sold between 5 to 6 weeks of age. Ideally, puppies should not be taken from their mothers until they’re at least 8 weeks old.

“Many sellers will lie about the puppy's age, and new owners do not realize how young their new family member is until their veterinarian examines it,” Dr. Burch said.

Puppies from puppy mills will sometimes have visible health issues as well. (Though just because a puppy appears healthy doesn’t mean he’s not from a puppy mill!)

“Some puppies can be underweight, have an unkempt coat, be experiencing diarrhea or have evidence of an upper respiratory infection with a snotty nose and goopy eyes,” Dr. Burch said.

Other puppies may be sick but appear to be totally fine, which is why it’s important to get any puppy checked out by a vet when you first get him.

Some other ways to tell if a puppy is from a puppy mill include:

  • The seller has many types of purebred dogs or “designer dogs.”
  • The seller will ship the dog to you without meeting you.
  • The seller won’t show people where the dogs are being kept and bred.
  • The seller doesn’t ask you any questions and doesn’t seem to care where the dog is going.

What’s being done to stop puppy mills?

Many nonprofit organizations, such as the ASPCA and the Humane Society of the United States, are working to end puppy mills by educating people about them.

“These organizations support federal legislators to press the United States Department of Agriculture (USDA) to enforce the Animal Welfare Act for these breeders,” Dr. Burch said. “If the USDA enforces the Animal Welfare Act, puppy mills will receive heavy fines and penalties for not following the law to ensure that these animals receive proper care.”

(The Animal Welfare Act puts into place minimum standards of care for certain animals, such as those who are bred for sale, but it’s not always enforced.)

How you can help stop puppy mills

The best way to help put an end to puppy mills is to avoid buying dogs from pet stores and from any places that seem sketchy, like flea markets.

“Instead of purchasing a puppy, adopt dogs from your local shelter or rescue,” Dr. Burch said.

You can find so many amazing dogs for adoption, and you won’t be supporting a puppy mill — win-win! You can even find puppies or purebred dogs at rescues if you have your heart absolutely set on a particular type of dog.

You’ll also be able to avoid many pitfalls of new dog ownership by going through a reliable rescue — for example, you’ll often work with an adoption counselor who can help you find a dog whose personality is the perfect match for you, and a good rescue will tell you upfront about any behavioral or health issues your new dog might have so you can make an informed decision.

And if you’re adopting online, do your research to make sure you’re not accidentally buying from a puppy mill, since puppy mill dogs are often sold online, and many of these sellers try to cover up that they’re puppy mills.

You can even adopt a puppy mill survivor to help him or her experience a life outside of the puppy mill!

“I recommend adopting an adult mill survivor, as they will need patient, loving adopters,” Dr. Burch said. “These animals also need a loving home, and you can help save a life when adopting from these organizations.”

Here are some other ways you can help end puppy mills:

  • Contact your local government officials to ask them to make puppy mills illegal or to enforce the Animal Welfare Act.
  • Donate to legitimate animal shelters and rescues.
  • Educate friends and family about puppy mills.
  • Report pet stores that sell puppies from puppy mills to local officials.
  • Support government officials who are animal-friendly.

Puppy mills are bad for dogs, and you should avoid buying from them and places that support them so you don’t perpetuate the cycle. If you’re looking for a puppy, consider adopting from a shelter or rescue — you might even save a puppy’s life.