You can tell by looking that a kitten is a kitten. But how do you know when that adorable little ball or fur is a fully grown cat? It turns out that kittens grow up fast. So enjoy every moment of kittenhood while it lasts.
Fully Grown at One Year Old
At 6 months old, a kitten starts showing the social traits of an adult kitty. At 1 year old, your cat is the equivalent of a 15-year-old teenager. So most cats reach maturity at a year old. There are a few exceptions. Maine coon cats take a few months longer to finish maturing, and Manx cats take five years to fully grow up.
Because cats remain kittens until they are a year old, they should be fed as such. The ASPCA recommends feeding your kitten a high-quality kitten kibble until he is 1 year old. It helps provide the energy and nutrition he needs while he is growing.
Spaying and Neutering
Cats do not have to be fully grown to be safely spayed or neutered. They can be spayed as young as 6 weeks old; kittens adopted from animal shelters often are. The recommended age for spaying a female or neutering a male is 5 to 7 months of age. Early spaying or neutering prevents the risk of reproductive cancers, unwanted litters and undesirable behaviors associated with mating, such as trying to get out or roaming to find mates and male cats spraying.
While kittens are nursing, their mother's milk provides them with immunity to most illnesses. Between weaning and adulthood, they develop the need for certain vaccines, called core vaccines, to protect them against specific illnesses. These usually are given twice between 10 and 14 weeks old and again at 1 year old. They include feline distemper, feline herpes virus type 1 and feline calicivirus. The rabies vaccine is given at 12 or 16 weeks of age and again at 1 year old.