There are many different reasons why buying your puppy from a reputable breeder is critical to both puppy health and temperament, but there are even more reasons to avoid buying from either a pet store or backyard breeder. Before getting into the specific reasons, it is important to define what a backyard breeder is. A backyard breeder is not the same as a small kennel owner, or a devoted dog owner that has one or two purebred or mixed breed dogs that they cherish and love and take excellent care of. These conscientious private breeders are often as knowledgeable and caring of their dogs and the promotion of the breed as the larger breeders. They may or may not enter their dogs into shows or competitions, however, they do put the needs and health issues of their dogs and any potential puppies above the profit they may make from the sale of puppies.
Backyard breeders are individuals that indiscriminately breed purebred or mixed breed dogs simply for resale purposes. They are interested in the profit from breeding, not about the puppies or the dogs themselves. Often, backyard breeders will have several different breeds of dogs, ranging from small to large breeds, and will not be involved in any breed associations or organizations. They will rarely, if ever, see the dogs as pets, rather they are livestock or potential profit for the backyard breeder.
Almost all breed registries and kennel clubs have an ethical standard that prevents breeders from selling puppies to pet stores or pet retailers. This is to prevent purebred dogs from being marketed without any spay and neuter aspect of the contract, resulting in these poor puppies often ending up with disreputable breeders or in puppy mills. It also means that breeders have no control over what type of person buys the puppies, leaving the door open for puppies to be sold to unsuitable, cruel or negligent individuals.
Puppy mills, also called puppy farms, are horrible places where dogs are kept in unsanitary and unsafe conditions, solely for the purpose of producing as many puppies per year as possible. These dogs are often kept in tiny spaces, and never allowed out except to breed. They are usually ill, genetically damaged, underfed and extremely emotionally and physically abused. Typically, they are untrained, and never have any human contact except to be moved from one area of the puppy mill to another. Usually they live in filthy conditions, and often die very young from health complications that go untreated. Food and water is often only provided infrequently, and thankfully most countries prohibit the operation of puppy farms under animal protection laws.
Unfortunately, most of the profit that puppy farms or puppy mills make is by selling litters of puppies to pet stores. Pet stores can buy cheap litters, which are often registered but absolutely not of show quality, and then sell them to unsuspecting buyers as "purebred, registered puppies". When owners try to show the dogs they are often very upset to find that the dog has disqualifying faults or simply does not meet breed standards. Obviously, not all pet stores do this but it is worth asking the pet store if they can vouch for or prove where the puppies came from before making a purchase.
Puppies from puppy farms or mills, hence many of the puppies from pet stores, are usually very unhealthy. At the very least they have worms, respiratory infections, and typically have digestive problems and dehydration due to the constant stress they are under. In addition to health related concerns with stress and distress, there are also all the other types of animals found within a pet store. While most diseases cannot be transferred from one species to another, there are some that can. Sometimes these diseases will not develop for a few weeks or months after you get the puppy home, leading to very high vet bills as the professional tries to determine the health issues with the puppy.
Buying a puppy from a pet store can actually support these deplorable puppy mills, plus most pet stores charge almost as much for their dogs as a reputable breeder. There is no health guarantee, and many times the registration information will prove to be inaccurate or incomplete, preventing you from registering the puppy.
Backyard breeders, using the definition provided above, are really just very small scale puppy mills. Since they do provide basic care for the puppies, they are not under the same legal restrictions as the larger puppy mills, and they typically do take somewhat better physical care of the dogs. It is important to realize that they may not take any better emotional care of the dogs, however, which will have a huge impact on the temperament of the puppy as it matures.
Backyard breeders, since they are not active in any showing or competition with their dogs, may not be aware of all the various aspects of breed standards. It is also very unlikely that they have a championship line in the dogs that they breed. Excellent small breeders, however, are very likely to have championship lines and wonderfully cared for and socialized dogs.
Usually, backyard breeders are not concerned about health checks or genetic testing of their dogs. Often there are serious genetic conditions within the dogs that are not noticed until the puppy has matured, and any health guarantee the backyard breeder may offer has long expired. Most of these breeders will not offer a health guarantee, or will offer a verbal agreement only, but not be willing to put it in writing. If the breeder will not put it in writing, it is critical to not purchase the puppy, as there is likely some genetic or health condition in the mother or father dog.
Purebred vs Show Quality
Many people that are new to purebred dogs mistakenly believe that any purebred puppy or dog with a pedigree and current registration number can be shown. This is completely false, and is often a way that disreputable or unprofessional breeders sell animals to people that they know cannot be shown. Each breed has its own breed standards, which are the physical and temperament attributes that the dog must possess when fully grown in oder to be entered into shows. Of course they must have their registration as well, but the attributes or standards are critical. A registered purebred dog that has a disqualification cannot be shown, and those with faults are typically not shown as they have no chance of winning or gaining recognition. Faults can be simple issues such as conformation, coat color or texture, shape of the ears or eyes, or even color of the skin on the nose. Disqualifications can be size, coat color, eye color or even the type of jaw or bite that the dog has. Without knowing the breed standards, buying from a backyard breeder, pet store or even a private individual is a risky business at best, especially if you wish to start showing the dog or puppy.