When Are Cats Not Considered Kittens Anymore?

Pretty soon that little guy will be all grown up.
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Kittens grow up quickly, doing much of their developing and reaching puberty as early as 6 months of age. Technically, though, your little one is still considered a kitten until he reaches around 1 year old. At this age, he'll be fully grown and considered an adult.

Kitten Development

Under 1 year of age, your kitten will do most, if not all of his growing. He'll reach sexual maturity between 6 months and 1 year. The little guy will also cut all of his adult teeth by around the 7-month point, according to Parkway Animal Hospital. He'll be increasing in size and weight as he grows into adulthood. During this time, he'll need proper nutrition that contains the extra protein, fats and calories he needs to develop healthy bones and tissues. Kitten food is designed specifically to meet your growing little buddy's needs and should be fed to him according to his weight, as the manufacturer recommends. Around his first birthday, he can be slowly switched onto an adult formula.

Health Care

Your little guy will need to follow the vaccine schedule recommended by your veterinarian so he develops a healthy immune system and can fight off diseases. Vaccines like the FVRCP need to be given two to three times while your little one is developing. After your furball reaches adulthood, he'll only need such vaccines every one to three years, depending on what the vet recommends. It's also important to bring a kitten to the vet regularly for his vaccines, neutering and regular health checks as he grows. Once he is a year old, you can bring him to the vet one to two times per year, depending on his health, because he'll be fully developed, recommends the Affectionately Cats Feline Veterinary Hospital and Boarding Suites website.

Activity and Adulthood

Age-wise, a 1-year-old kitten is the equivalent of a 15-year-old teenager, according to the American Animal Hospital Association. He's actually the equivalent of a human, 18-year-old adult at 15 months of age, at which point he'll be all grown up. While your adult kitty will still tear through your home, he probably won't be quite the little hyperactive rascal he was as a kitten. As he reaches adulthood, he'll start to settle down. While he'll still be active, it's important to engage your grown-up kitty in 10 to 15 minutes of play two times per day, recommends the ASPCA Kids website. This is to prevent those calories previously used for growth from turning into extra pounds on his adult frame.


A kitten requires that you feed him several smaller meals throughout the day so he can get the calories he needs into his small tummy. As he ages and his tummy grows, you can feed him an adult-formula food in two larger meals by the 12-month mark.

Socialize your feline friend as a kitten prior to adulthood so that he is used to people and friendly as an adult. Once he's all grown up he'll be set in his ways.

While a kitten may not be considered an adult until he reaches 1 year old, he is capable of reproducing at half this age, even as he's still developing himself. This is why it's important to get your little guy or girl fixed so that you won't be dealing with unwanted kittens even as your kitty is still considered one.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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