A puppy is a juvenile dog. Some puppies can weigh 1–1.5 kg (2.2–3.3 lb), while larger ones can weigh over 7 kg (15 lb). All puppies are underdeveloped at birth (display altriciality) but healthy puppies grow quickly thereafter. A puppy's coat color may change as the puppy grows older, as is commonly seen in breeds such as the Yorkshire Terrier. Puppy refers specifically to young dogs,[1] while pup may be used for other animals such as wolves, seals, giraffes, guinea pigs, rats or sharks.[2]