Dog breeding

Line breeding is differentiated from inbreeding by excluding pairings between parents and offspring, and between full siblings.

Since it is difficult to determine the exact date of ovulation, errors are often made in calculating gestation period.

[5] It is believed that when human civilization moved towards agrarian societies, dogs were selectively bred for smaller size and more docile behavior.

[7] The example of canine neoteny goes even further, in that the various dog breeds are differently neotenized according to the type of behavior that was selected.

[11] Dogs bred for show rather than performance tended to develop more exaggerated and extreme features to meet breed standards.

The Shar Pei is an example of how differing breed standards can influence the direction breeders take a dog and which traits are exaggerated.

Access to records allows a breeder to analyze the pedigrees and anticipate traits and behaviors that may be passed onto offspring.

Breeders have to abide by the rules of the specific organization to participate in its breed maintenance and development programs.

The rules may apply to the health of the dogs, such as joint x-rays, hip certifications, and eye examinations; to working qualities, such as passing a special test or achieving at a trial; to general conformation, such as evaluation of a dog by a breed expert.

However, many registries, particularly those in North America, are not policing agencies that exclude dogs of poor quality or health.

[15] During the early formative years of many breeds, breeders often crossed closely related dogs to create specific phenotypes, resulting in increased incidence of breed-specific genetic diseases.

Also, special organizations such as the Orthopedic Foundation for Animals collect data and provide it to breeders, as well as to the general public.

Some scientific researchers argue that advances in artificial reproduction technology for the purposes of dog breeding can be helpful, but also have "detrimental impacts" when overused, overriding natural selection principles.

These scientists call for a deeper understanding of natural selection, leading to a more naturalistic approach in dog breeding.

Data collected through owner reports suggests that genetic diversity has an effect on dogs' lifespan.