A puppy is a juvenile dog. Some puppies may weigh 1–3 lb (0.45–1.4 kg), while larger ones can weigh up to 15–23 lb (6.8–10 kg). All healthy puppies grow quickly after birth. A puppy’s coat color may change as the puppy grows older, as is commonly seen in breeds such as the Yorkshire Terrier. In vernacular English, puppy refers specifically to dogs while pup may often be used for other mammals such as seals, giraffes, guinea pigs, or even rats.
Born after an average of 63 days of gestation, puppies emerge in an amnion that is bitten off and eaten by the mother dog. Puppies begin to nurse almost immediately. If the litter exceeds six puppies, particularly if one or more are obvious runts, 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 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 such as dog treats.