A puppy is a juvenile dog. Some puppies can weigh 1–3 lb (0.45–1.36 kg), while larger ones can weigh up to 15–23 lb (6.8–10.4 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.[1] 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.[2] The mother dog 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.[3]
Puppies are born with a fully functional sense of smell but can't 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 eyes about nine to eleven days following birth. At first, their retinas 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 to four weeks old, puppies usually begin to growl, bite, wag their tails, and bark.[4]
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.
A kitten (also known as a kitty or kitty cat) is a juvenile cat. After being born, kittens are totally dependent on their mother for survival and do not normally open their eyes until after seven to ten days. After about two weeks, kittens quickly develop and begin to explore the world outside the nest. After a further three to four weeks, they begin to eat solid food and grow adult teeth. Domestic kittens are highly social animals and enjoy human companionship.
Etymology and development
The word "kitten" derives from the Middle English word kitoun, which in turn came from the Old French chitoun or cheton.[1] The big cats are called "cubs" rather than kittens; either term may be used for the young of smaller wild felids, such as ocelots, caracals and lynx, but "kitten" is usually more common for these species.
A feline litter usually consists of two to five kittens.[3] The kits are born after a gestation that lasts between 64 and 67 days, with an average length of 66 days.[3] Kittens emerge in a sac called the amnion, which is bitten off and eaten by the mother cat.[4]
For the first several weeks, kittens are unable to urinate or defecate without being stimulated by their mother.[5] They are also unable to regulate their body temperature for the first three weeks, so kittens born in temperatures less than 27 °C (81 °F) can die from hypothermia if their mother does not keep them warm.[6] The mother's milk is very important for the kittens' nutrition and proper growth. This milk transfers antibodies to the kittens, which helps protect them against infectious disease.[7] Newborn kittens are unable to produce concentrated urine, and so have a very high requirement for fluids.[8] Kittens open their eyes about seven to ten days after birth. At first, the retina is poorly developed and vision is poor. Kittens are not able to see as well as adult cats until about ten weeks after birth.[9]
Kittens develop very quickly from about two weeks of age until their seventh week. Their coordination and strength improve. They play-fight with their litter-mates and begin to explore the world outside the nest or den. They learn to wash themselves and others as well as play hunting and stalking games, showing their inborn ability as predators. These innate skills are developed by the kittens' mother or other adult cats, who bring live prey to the nest. Later, the adult cats demonstrate hunting techniques for the kittens to emulate.
Dogs V Çats
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