Dog breeding

Dog breeding is the practice of mating selected dogs with the intention of maintaining or producing specific qualities and characteristics. When dogs reproduce without such human intervention, their offspring's characteristics are determined by natural selection, while "dog breeding" refers specifically to the artificial selection of dogs, in which dogs are intentionally bred by their owners. Breeding relies on the science of genetics, hence a breeder who is knowledgeable on canine genetics, health, and the intended purpose of the dogs attempts to breed suitable dogs. The female parent of puppies is referred to as the dam and the male parent is referred to as the sire. A litter consists of the puppies born from the same pregnancy. A whelp is a newborn puppy and giving birth to dogs is called whelping. Dogs commonly give birth in a whelping box, a simple box or pen provided to the dam to help shelter and contain the puppies. A person who intentionally mates dogs to produce puppies is referred to as a dog breeder. Line breeding is the planned breeding of dogs with their relatives. This is done to strengthen the appearance of specific desired traits in offspring. Line breeding is differentiated from inbreeding by excluding pairings between parents and offspring, and between full siblings. Outcrossing is the planned breeding between two unrelated dogs, used to increase genetic diversity in a breed and decrease genetic issues or abnormalities inherited from line breeding or inbreeding. Canine reproduction#The reproductive cycle Dogs reach puberty between 6 and 24 months old, at which age female dogs will start having an estrous cycle. There are four stages of estrous: proestrus, estrus, diestrus, and anestrus. A dog in estrus, also known as being "in heat", can become pregnant during this 3- to 21-day period. Canine reproduction#Gestation and littersGestation in a dog is 63 days in length, if measured from the day of ovulation. Since it is difficult to determine the exact date of ovulation, errors are often made in calculating gestation period.