Backyard Breeder is a general term, often considered derogatory, used in USA to describe people who breed animals, often without registration. In some cases the animals are inbred narrowly for looks with little regard to health. The term most often is used to describe certain types of breeders of dogs and horses. The term is used in this sense by the Animal Welfare community, The American Society for the Prevention of Cruelty to Animals (ASPCA), larger established breeders and breed clubs in contrast to the more positive term, "reputable breeder" that describes operations that use responsible methodology and practices.
It implies either or both of home breeding for non-commercial reasons or a for-profit small commercial operation that does not adhere to good breeding, care and sale practices. Larger commercial operations of a similar type that breed dogs are usually termed a puppy mill (especially in North America) or puppy farm. However, as large kennels usually require licensing, many puppy mills are licensed with the USDA.
Many small breeders resent the term and its use. Some do so because they assert that they run small, but high-quality "boutique" operations. Others argue that their unregistered animals are highly desirable as companion animals and economical for ordinary people to purchase. Both groups deny that they contribute to low quality or produce unwanted animals.
- Ignorance of selective breeding goals and techniques, and lack of familiarity with the breed standard of the type of animal being bred.
- Exclusive focus on the breed standard involving little genetic screening or co-efficient of Inbreeding calculations.
- Breeding of a working breed for appearance rather than working ability. This is a criticism also levelled at 'reputable' breeders who breed for the show ring - in some cases distinct working and show strains have emerged.
- Lack of adequate veterinary care and maintenance.
- Excessive breeding from individual females, to the detriment of their health.
- Sale of animals with genetic disorders or undisclosed illnesses before they become evident to buyers.
- Lack of screening of potential owners or the provision of suitable information to prevent buyers from purchasing an animal that may be inappropriate for them or their lifestyle.
- Breeding of animals for illegitimate reasons, such as for horse slaughter or the usually illegal sports of baiting and dog fighting or to defend venues of criminal activity. Dog fanciers generally believe that such ill-bred dogs are the reason for the bad reputation of some breeds in the public perception, and the resulting breed-specific legislation. The production of "PMU foals" from pregnant mares bred solely for their urine production (used in the making of the drug Premarin) is also widely condemned due to the frequency with which the progency of such breedings are shipped directly to slaughter.
- Breeding without concern for the possibility of finding homes, though commercial means or otherwise, for offspring, thus adding to the population of unwanted dogs and to the slaughter of horses for meat.
There are campaigns to reduce or eliminate this type of breeding in several countries  as well as video campaigns by groups like ASPCA that emphasize the importance of understanding the responsibilities associated with owning an animal. The primary concern of the Animal Welfare community is that this type of breeding is the major source of pet animals and that overproduction has led to overpopulation and hence to welfare issues and the putting down of animals for no other reason than the lack of suitable home. The glamorization of Chihuahuas, which some claim has been generated by Hollywood, has had devastating outcomes for dogs and their adopted owners. Specifically, dog owners like Paris Hilton and commercial-star Gidget the Taco Bell chihuahua as well as films like Beverly Hills Chihuahua have been directly cited as blameworthy. Most dog breed societies and Kennel Clubs have similar concerns but place rather more stress on issues relating to breed standardization and quality.
In the horse world, the slaughter issue is closely linked to backyard breeding, as many poorly bred, unregistered horses have no value other than to horsemeat buyers.
There are many animal adoption alternatives that potential pet owners can consider, including: The Humane Society of the United States, European animal rescue  local animal adoptions that can be found on the rescue and adoption portion of Pet Finder and through local newspapers (ex: The Chicago Tribune ).
- The Obama family dog saga. LA Times.
- Rescue groups paint a sad story of Iowa’s puppy mills. The Messenger.
- ASPCA Cruelty Glossary ASPCA website/
- GREYHOUND OVER BREEDING Campaigning for the Abolition of Betting on Greyhounds
- Puppies are not Toys ASPCA YouTube
- California animal shelters' plague: Not a rain of frogs, but a rain of Chihuahuas LA Times
- 2-year-old Chihuahua Rosie Before She was Rescued Everything Rosie
- Taco Bell Dog Spurs Pet Revolution Philly.com
- The Chihuahua Boom About.com
- California's chihuahua problem? Blame it on Paris Hilton The Guardian
- Directory of Animal Shelters in Europe
- Animal Shelters and Rescues Petfinder.com
- Pets in Need of Homes Chicago Tribune