A puppy is a juvenile

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

, generally one less than 12-18 months old. Puppies are markedly underdeveloped and dependent on their mothers at birth (displaying ''

altriciality Precocial species in birds and mammals are those in which the young are relatively mature and mobile from the moment of birth or hatching. They are normally nidifugous, meaning that they leave the nest shortly after birth or hatching. Altricial ...

''), but healthy puppies grow quickly and begin walking thereafter. Puppies generally weigh shortly after birth, depending on the breed. A puppy's coat colour may change as the puppy grows older, as is commonly seen in breeds such as the

Yorkshire Terrier The Yorkshire Terrier, also known as a Yorkie, is a British breed of toy dog of terrier type. It is among the smallest of the terriers and indeed of all dog breeds, with a weight of no more than . It originated in the nineteenth century in the ...

. ''Puppy'' refers specifically to young dogs, while ''pup'' may be used for other animals such as

wolves The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, including the dog and dingo, though gr ...

seals Seals may refer to: * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to impress an emblem, used as a means of a ...

giraffes The giraffe is a large African hoofed mammal belonging to the genus ''Giraffa.'' It is the tallest living terrestrial animal and the largest ruminant on Earth. It is classified under the family Giraffidae, along with its closest extant re ...

guinea pigs The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy ( ), is a species of rodent belonging to the genus ''Cavia'', family Caviidae. Breeders tend to use the name "cavy" for the animal, but "gui ...

rats Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), '' Bandicota'' (bandicoot ...

, or

sharks Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

Prenatal development

Dogs go through

prenatal development Prenatal development () involves the development of the embryo and of the fetus during a viviparous animal's gestation. Prenatal development starts with fertilization, in the germinal stage of embryonic development, and continues in fetal de ...

before they are born, just like all animals do. The germinal stage, the embryonic stage, and the fetal stage are the three phases that make up this development. The first stage of prenatal growth in dogs is known as the germinal stage, which starts at fertilization and lasts for about two weeks. The fertilized egg, also known as the zygote, travels through the fallopian tube to the

uterus The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the hollow organ, organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic development, embryonic and prenatal development, f ...

during this period while undergoing rapid cell division. The

placenta The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas, and waste exchange between ...

, which will feed the growing puppy, is formed once the zygote enters the uterus and settles in the uterine wall. The embryonic period lasts from about day 14 of pregnancy until day 28 or so. With the growth of important organs and body systems, the embryo starts to take on a more recognizable shape at this stage. This involves the development of the digestive system, brain, heart, and lungs. An ultrasound can show the embryo at this time, which is about the size of a grape. Around day 28 is when the fetal period starts, and it lasts until day 63, when the puppy is born. The puppy's organs and systems continue to develop and refine during this period of growth and development. It also involves the ability to control its own body temperature as well as the maturation of the senses, such as hearing and sight. The puppy is completely developed and prepared for birth by the time the fetal period is over.

Development

Puppies are born after an average of 63 days of

gestation Gestation is the period of development during the carrying of an embryo, and later fetus, inside viviparous animals (the embryo develops within the parent). It is typical for mammals, but also occurs for some non-mammals. Mammals during pregn ...

, emerging in an

amnion The amnion (: amnions or amnia) is a membrane that closely covers human and various other embryos when they first form. It fills with amniotic fluid, which causes the amnion to expand and become the amniotic sac that provides a protective envir ...

that is bitten off and eaten by the mother dog. Puppies begin to

nurse Nursing is a health care profession that "integrates the art and science of caring and focuses on the protection, promotion, and optimization of health and human functioning; prevention of illness and injury; facilitation of healing; and alle ...

almost immediately. If the

litter Litter consists of waste products that have been discarded incorrectly, without consent, at an unsuitable location. The waste is objects, often man-made, such as aluminum cans, paper cups, food wrappers, cardboard boxes or plastic bottles, but ...

exceeds six puppies, particularly if one or more are obvious

runt In a group of animals (usually a litter of animals born in multiple births), a runt is a member which is significantly smaller or weaker than the others.. Owing to its small size, a runt in a litter faces disadvantage, including difficulties in c ...

s, human intervention in hand-feeding the stronger puppies is necessary to ensure that the runts get proper nourishment and attention from the mother. As they reach one month of age, puppies are gradually

weaned Weaning is the process of gradually introducing an infant human or other mammal to what will be its adult diet while withdrawing the supply of its mother's milk. In the UK, weaning primarily refers to the introduction of solid foods at 6 mont ...

and begin to eat solid food. The mother may regurgitate partially digested food for the puppies or might let them eat some of her solid food. The mother usually refuses to nurse at this stage, though she might let them occasionally nurse for comfort. At first, puppies spend the large majority of their time sleeping and the rest feeding. They instinctively pile together into a heap, and become distressed if separated from physical contact with their littermates by even a short distance. Puppies are born with a fully functional sense of smell. They are unable to open their eyes. During their first two weeks, a puppy's senses all develop rapidly. During this stage the nose is the primary sense organ used by puppies to find their mother's teats, and to locate their littermates, if they become separated by a short distance. Puppies open their

eye An eye is a sensory organ that allows an organism to perceive visual information. It detects light and converts it into electro-chemical impulses in neurons (neurones). It is part of an organism's visual system. In higher organisms, the ey ...

s about nine to eleven days following

birth Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...

. At first, their

retinas The retina (; or retinas) is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then proce ...

are poorly developed and their vision is poor. Puppies are not able to see as well as adult dogs. In addition, puppies' ears remain sealed until about thirteen to seventeen days after birth, after which they respond more actively to sounds. Between two and four weeks old, puppies usually begin to growl, bite, wag their tails, and bark. Puppies develop very quickly during their first three months, particularly after their eyes and ears open and they are no longer completely dependent on their mother. Their coordination and strength improve, they spar with their littermates, and begin to explore the world outside the nest. They play wrestling, chase, dominance, and tug-of-war games.

Socialization

Puppies are highly social animals and spend most of their waking hours interacting with either their mother or littermates. When puppies are socialized with humans, particularly between the ages of eight and twelve weeks, they develop social skills around people. Those that do not receive adequate socialization during this period may display fearful behavior around humans or other dogs as adults. The optimum period for socialisation is between eight and twelve weeks; professional animal trainers and the

American Kennel Club The American Kennel Club (AKC) is a 501(c)(4) nonprofit breed registry, registry of purebred dog pedigree (animal), pedigrees in the United States. In addition to maintaining its pedigree registry, this kennel club also promotes and sanctions eve ...

advise puppies should be introduced to "100 People by 12 Weeks" and have encountered a wide and varied selection of people and environments.

Docking and declawing

The practice of docking began primarily as a preventive measure for injury among working dogs. Docking is now primarily performed for purely cosmetic reasons, and some breeds traditionally have their tails cropped anywhere from slightly to almost entirely.Serpell, James A. ''Companion Animals And Us: Exploring the Relationships Between People and Pets'', 2000, page 307 Many countries now ban cropping and docking for cosmetic purposes, including Australia, parts of Canada, the majority of the European countries (Austria, Greece, Finland, Netherlands, Italy, the Czech Republic, Turkey, Poland, Slovakia, England, Scotland, Slovenia, Ireland, Norway and Sweden), while others, such as the United States, permit it. As of 2008, the practice is opposed by the

American Veterinary Medical Association The American Veterinary Medical Association (AVMA) is an American not-for-profit association founded in 1863 that represents more than 105,000 veterinarians. The AVMA provides information resources, continuing education opportunities, publicat ...

.AVMA.org
AVMA opposes cosmetic ear cropping, tail docking of dogs - December 15, 2008 Some breeders also prefer to declaw the dogs to prevent future injuries caused by scratching, or in the case of

dewclaw A dewclaw is a digit – vestigial in some animals – on the foot of many mammals, birds, and reptiles (including some extinct orders, like certain theropods). It commonly grows higher on the leg than the rest of the foot, such that in di ...

s, ingrown and ripped-off nails. Docking and declawing procedures are usually performed within the first few days after birth, by a

veterinarian A veterinarian (vet) or veterinary surgeon is a medical professional who practices veterinary medicine. They manage a wide range of health conditions and injuries in non-human animals. Along with this, veterinarians also play a role in animal r ...

, or by an experienced breeder.

Gallery

File:ACD Silverbarn's Ronja x.jpg,

Australian Cattle Dog The Australian Cattle Dog, or simply Cattle Dog, is a breed of herding dog developed in Australia for droving cattle over long distances across rough terrain. This breed is a medium-sized, short-Coat (dog), coated dog that occurs in two main ...

puppy File:Abandoned Dog.jpg, A

mongrel A mongrel, mutt, or mixed-breed dog is a dog that does not belong to one officially recognized breed, including those that result from intentional breeding. Although the term ''mixed-breed dog'' is sometimes preferred, many mongrels have no kn ...

puppy File:Westie pups.jpg,

West Highland White Terrier The West Highland White Terrier (commonly shortened to Westie) is a dog breed, breed of dog from Scotland with a distinctive white harsh coat and somewhat soft white undercoat. It is a medium-sized terrier, though with longer legs than other ...

puppies File:St. Bernard puppy.jpg, St. Bernard puppy File:Image-Cavapoo puppy.JPG,

Cavapoo The Cavapoo (American English) or Cavoodle (Australian English) is a crossbreed of a Cavalier King Charles Spaniel and a Poodle. The cavapoo is speculated to have been first bred by designer dog breeders in Australia in the 1950s as a companion ...

puppy File:Beulah at Five & A Half Weeks on Jan Coffman's Farm, Walkerville, MD June 1999 by Asilverstein.jpg,

Bloodhound The bloodhound is a large scent hound, originally bred for hunting deer, wild boar, rabbits, and since the Middle Ages, for tracking people. Believed to be descended from hounds once kept at the Abbey of Saint-Hubert, Belgium, in French it is ...

puppy File:Chihuahua puppy 001.jpg, Chihuahua puppy File:Szczenie Jack Russell Terrier3.jpg, Jack Russell Terrier puppy File:Puggle puppy (cropped).jpg ,

Puggle A puggle is a dog crossbreed, dog crossbred from a Pug and a Beagle. The breed originated in the 1990s in the United States. History The puggle originated from accidental matings. The first planned cross between a pug and a beagle took place ...

puppy File:Basenji puppies.jpg , Newborn

Basenji The Basenji () is a breed of hunting dog created from stock that originated in Central Africa, including in the Republic of the Congo and other adjacent tropical African countries. The Fédération Cynologique Internationale places the Basenji ...

puppies File:German Spitz puppy.jpg, German Spitz puppy File:Puppy on Halong Bay.jpg, A little

puppy on the shore, on

Halong Bay Halong may refer to: * Ha Long Ha may refer to: Agencies and organizations * Health authority, a former type of administrative organisation of the NHS in England and Wales * Hells Angels Motorcycle Club * Highways Agency (renamed ''Highways En ...

File:Raskal.jpg ,

puppy File:Two red and white haired shih tzu littermates.jpg, Two Shih Tzu puppies File:President Lyndon B. Johnson and his puppies.jpg, President

Lyndon B. Johnson Lyndon Baines Johnson (; August 27, 1908January 22, 1973), also known as LBJ, was the 36th president of the United States, serving from 1963 to 1969. He became president after the assassination of John F. Kennedy, under whom he had served a ...

with a basket of puppies in 1966

References

External links

Great breeds for First-Time Dog Owners
from the AKC
Legislation and rules - Be your dogs best friend and a good neighbor
from the AKC {{Authority control Dogs