Report highlights. Commercial dog breeding facilities or “puppy mills” are defined by overcrowding and unsanitary conditions. This is primarily due to the overwhelming number of illegal mills as well as licensed mills that fail to follow state and/or federal animal cruelty laws.

  • 70% of puppy mills operate illegally.
  • About half of puppies born in mills survive their first 12 weeks.
  • 10,000+ facilities, licensed and unlicensed, are actively producing.
  • 0ver a half-million dogs are kept solely for breeding purposes.
  • Up to 4.3 million puppies are born in mills every year.

Puppy Mill Populations

The true population of puppy mill dogs is unknown. Mill populations are in constant flux due to births, sales, deaths, etc. Additionally, the federal agency in charge of keeping those numbers – the U.S. Department of Agriculture (USDA) – stopped making them accessible to the public in 2017.

  • 167,388 breeding dogs lived in licensed facilities in 2017.
  • By current estimates, the breeding dog population in legal mills exceeds 194,000 animals.
  • 660,000 is the estimated total for breeding dogs in all puppy mills.
  • 30% of breeding animals are male.
  • Legal facilities report over a million puppies born in a year.
  • Among all facilities, legal and illegal, upwards of 4 million dogs are born annually.

Breeding in Puppy Mills

Most breeding dogs in mills are female. These dogs are often bred at much earlier ages than is recommended by veterinarians and animal specialists. This can lead to health problems in breeding dogs, some of which can be passed down through generations of their offspring.

  • 460,000 total breeding animals are female.
  • Some puppy mills breed dogs as early as 4 months of age.
  • 6 years is the average age breeding females stop producing.
  • A female breeding dog’s “career” may last a little more than 5.5 years.
  • 9.4 is the average number of puppies each female produces in a year.
  • 77,000 breeding females are “worn-out” each year and replaced with new dogs.

Health in Puppy Mills

Studies show that dogs born and/or kept in commercial breeding facilities exhibit significantly higher rates of health problems both mental and physical. Specialists attribute these health problems to poor breeding, malnutrition, lack of socialization and other improper care.

  • Mill puppies are 41.6% more likely to develop health issues than the general population of dogs.
  • Common problems in mills include dogs living in their own filth with multiple animals to a cage.
  • Studies by animal behavioral scientists have shown that mill puppies exhibit behavior consisten with poor mental health into adulthood.
    • Mill dogs are more likely to struggle with house-training.
    • Mill dogs exhibit higher rates of fear, both social and non-social.
    • Mill dogs have also been observed to exhibit low energy and lack of trainability.

Common Hereditary Diseases

Improper breeding practices can result in disorders and diseases that may be passed from one generation to the next. Some of these disorders are not immediately obvious; some may not make themselves known until the animal has reached a certain age, which is why people who purchase these animals may not realize right away that their puppy is ill.

  • Epilepsy
  • Heart disease
  • Kidney disease
  • Deafness
  • Respiratory defects
  • Musculoskeletal disorders
    • Hip dysplasia
    • Luxating patellas
    • Polydactly
  • Endocrine disorders
    • Diabetes
    • Hyperthyroidism
    • Cushing disease
  • Blood disorders
    • Anemia
    • Von Willebrand disease
    • Hemophilia
  • Eye problems
    • Retinal atrophy
    • Glaucoma
    • Cataracts

Common Communicable Diseases

In order to maximize profits, commercial breeders must produce a high number of dogs in a short period. This limits recovery time for breeding females. In some cases, dogs are bred as early and as often as physically possible to the detriment of their health and the health of their puppies; their puppies are more succeptible to diseases, including illness that can endanger people. Among the most common communicable diseases found in mills, more than a third are human communicable (in bold).

  • Giardia
  • Parvovirus
  • Distemper
  • Pneumonia
  • Kennel cough
  • MRSA
  • Mange
  • Fleas
  • Ticks
  • Intestinal parasites
  • Heartworm
  • Chronic diarrhea
  • Upper respiratory infections

Death in Puppy Mills

Note that there is no data regarding the number or nature of deaths in puppy mills, as commercial breeders are not required to report deaths of animals under their care. Any numbers regarding deaths in mills must be estimated and/or extrapolated based on available data.

  • Excluding breeding animals, as many as 2 million dogs die in puppy mills each year.
  • Breeding animals are usually killed once they are no longer able to produce.
  • Puppies taken from their mothers too young (as is common practice in mills) are prone to illness and death.
  • Dogs rarely receive veterinary care, leading to preventable deaths.
  • Sometimes mill dogs are purposefully euthanized; these procedures rarely use legal or approved methods.
    • Dogs may be gassed using improvised gas chambers.
    • Shooting and drowning are also common methods of euthanasia in puppy mills.

The Puppy Pipeline

The path a puppy takes from birth in the mill to its final owner may be referred to as the “puppy pipeline.” From the mill the pipeline for most dogs includes the truck (transport), the brokerage and/or the pet shop. Investigations have uncovered abuse and neglect at many points in this pipelin, from improper transportation to unsanitary housing.

  • The USDA estimates that just over 2 million puppies are sold in pet stores.
  • Almost half of mill puppies are purchased by pet shops, chains, and superstores.
  • 90% of pet store dogs were born in puppy mills.
  • Investigators routinely find ill, underweight, and abused animals these pet stores.
  • Breeders associations discourage or disallow their members from selling to pet stores.
  • 34% of pet dogs come from breeders.
  • Some mills sell their animals in states where puppy mills are illegal or strictly regulated.


Terms used along the puppy pipeline can be confusing. Animal rights groups refer to this language as “doublespeak” and claim that it is deliberately designed to mislead pet owners.

  • A “breeder” may refer to any person who arranges for two animals to produce spawn.
  • A “dealer” or “broker” is an individual or organization that buys mill puppies and sells them to stores, to other brokers, or directly to consumers.
  • “USDA Class A” refers to a licensed breeder that only sells animals bred in their facility.
  • “USDA Class B” refers to a licensed broker that purchases and/or resells warm-blooded animals.
  • “Transporters” are people who move animals from one place to another.

How and Where Mill Puppies are Sold

Puppy mills’ biggest customers are not pet owners. Pet shops, chains, and superstores purchase dogs in mass amounts, often indiscriminately. Brokers make it more difficult for consumers to determine the origin of a puppy. Unhealthy dogs are such a problem in these stores that state and federal agencies warn consumers about purchasing from such stores, with some even passing laws to reduce instances of animal cruelty.

  • For every 50 licensed breeders, there are 13 licensed brokers.
  • 2/3 of pet store puppies are shipped by brokers.
  • Many Class B animal brokers have been caught breeding animals themselves.
  • Legitimate breeders are highly unlikely to sell their animals using brokers.
  • More and more, brokers are moving online to avoid inspection and transparency.

Online Brokers

Watchdog groups report a steady increase in online brokerages – for which there are virtually no regulations – masquerading as legitimate breeders or even as animal shelters/rescues.

  • Online brokers often refer to themselves as “puppy concierges” or “puppy finders,” using their web site to “match” a user with one or more breeders.
  • 36% of dog owners use the internet to find their pet.
  • The USDA reports a higher rate of illness among dogs purchased online than those purchased in person.
  • The Better Business Bureau reports a high rate of scam complaints regarding online pet sales.
  • The Humane society received 5,000 complaints between 2007 and 2017 about online pet sales operations.

Legality of Puppy Mills

In order to operate legally, puppy mill owners are required to register with the Animal and Plant Health Inspection Service (APHIS) under the USDA. Most do not. While there is no one official definition of a puppy mill, a U.S. district court in defined puppy mills as “dog breeding operation[s] in which the health of the dogs is disregarded in order to maintain a low overhead and maximize profits.”

  • 3,000 puppy mills are registered with APHIS.
  • 70% of all puppy mills continue to operate illegally.
  • There are 7,000 illegal puppy mills nationwide.
  • $500,000 is how much it costs taxpayers to bust a single illegal breeding operation.
  • A single puppy mill may keep anywhere from 5 to over one thousand dogs.
  • The Animal Welfare Act (AWA) of 1966 regulates animal commerce; like many laws, however, its language contains loopholes.
    • The AWA’s language does not contain the term “puppy mill(s).”
    • For dogs, the AWA delineates standards for survival (as opposed to standards for humane care.)
    • Dealers or breeders that sell directly to the public or within their own state are not subject to AWA regulations.
    • APHIS agents may conduct inspections to determine if someone is in violation of the AWA.
    • The AWA has been ammended 8 times; none of these ammendments relate to puppy mills, but pending legislation often does.

State Laws about Puppy Mills

The AWA protects some animals at a federal level, but many states have additional regulations for puppy mills, pet stores, and/or supply lines. The AWA contains language that allows for states to make their own animal rights’ laws to fortify federal regulations. States with a poor track record of prosecuting animal rights violations tend to have a higher number of commercial breeders and brokers.

  • In most states, puppy mills are legal.
  • 31 states require puppy mills to obtain a license from the state in addition to the federal license.
  • 14 states require puppy mills to undergo a State inspection.
  • 4 states – Louisiana, Oregon, Virginia and Washington – place limits on the number of dogs a single mill can keep.
  • 16 states have no laws to regulate breeding facilities.
  • Missouri has a higher rate of animal abuse in commercial facilities than any other state by far.
  • Other states with high rates of unchecked and repeated abuse in commercial facilities include Ohio, Kansas, and Wisconsin.

Additional Animal Protections

Veterinarians, breeding associations, and animal rights groups support outlawing all puppy mills. Targeting mills directly, however, is often ineffective. Lawmakers and animal rights groups now focus on alternative ways to subvert the commercial breeding industry.

  • A “puppy lemon” law is designed to help pet owners who purchase a sick animal gain some recourse.
  • Some states have increased regulations or on pet stores nationwide, including outright bans.
    • The State of California prohibits all pet stores from buying from commercial breeders.
    • At least a dozen more states have passed or are expected to pass similar legislation, including Georgia, Maryland, Florida, and Ohio, among others.
  • 300 U.S. cities and counties have have passed addtional laws designed to subvert the commercial breeding industry.
    • The City of Philadelphia has banned all retail pet sales.
    • Cook County, Illinois has outlawed the purchase of animals from commercial breeding facilities.

Contribution to Animal Homelessness and Death

Pet owners are just as likely to buy a puppy mill dog as they are to adopt from a shelter. Animal rights groups point out that if no one purchased their animals from mills, more pet owners would likely find a companion at an animal shelter or rescue. Additionally, animals that don’t find permanent homes face euthanasia.

  • 1 out of every 10 dogs born will find a permanent home.
  • 1-in-3 pet dogs come from puppy mills.
  • Animal shelters take in an estimated 3.3 million dogs annually.
  • At least 1-in-4 of these animals are euthanized; some euthanizations are due to lack of shelter resources.
  • The World Health Organization estimates there are 200 million stray dogs worldwide, all of which pose a potential health risk.

Report Illegal Puppy Mills

To report an unlicensed puppy mill, animal abuse, or other violation of the AWA, please immediately contact APHIS at the USDA, local authorities and/or animal welfare nonprofits.


  1. Merriam-Webster Definition of Puppy Mill
  2. The Truth About Puppy Mills
  3. Stopping Puppy Mills
  4. Pet Store Doublespeak
  5. Shelter Intake and Surrender: Pet Statistics”
  6. 11 Facts About Puppy Mills
  7. Humane Society Fact Sheets and Resources
  8. Mental Health of Dogs Formerly Used as ‘Breeding Stock’ in Commercial Breeding Establishments
  9. Pets by the Numbers
  10. Animal Welfare Act
  11. Animal Care Factsheet: The Animal Welfare Act
  12. Cities Are Fighting Back Against Puppy Mills
  13. HSVMA Veterinary Report on Puppy Mills
  14. Does America Have Enough Dogs for All the People Who Want One?
  15. A Closer Look at Puppy Mills
  16. HSVMA Report on Puppy Mills
  17. Perspectives From the Field: Illegal Puppy Imports Uncovered at JFK
  18. USDA Removes Inspection Reports
  19. HSUS: State Puppy Mill Laws
  20. Pathogenesis of Endocrine Diseases in Animals
  21. Animal Diagnostic Center: Hemophilia A
  22. 577 F.Supp. 958 (1984) Avenson vs. Zegart
  23. Puppy Mills: Millions of Dogs Suffer Needlessly to Create Pets
  24. The Puppy Pipeline
  25. Ending Retail Puppy Sales Standing Against Puppy Mill Cruelty
  26. Another Reason Not to Buy Puppies from Puppy Mills
  27. Shelter Intake and Surrender Statistics
  28. The Internet is a ‘Wild West’ for Pet Sales
  29. Animal Shelter Euthanasia
  30. The Global Stray Dog Population Crisis and Human Relocation
  31. Annual Horrible Hundred Report: 2020
  32. NY Kennel Owner Admits Gassing 93 Dogs with Farm Engine
  33. About Puppy Mills
  34. Puppy Mill Brokers