Glossary

Adult cat

A fully grown cat, roughly from two to six years old, in its prime and needing steady care, exercise and a weight-controlled diet.

Also called: prime cat, adult cats, fully grown cat

Different guidelines draw the lines in different places, but an adult cat is usually one between about two and six years old, a phase sometimes called the prime. In the newer veterinary scheme, adulthood covers a longer span of roughly one to ten years. The cat has reached its full size, and its behaviour has settled.

Adults are generally healthy, which can lull owners into skipping vet visits. A yearly check-up is the usual advice, to keep vaccinations and parasite control up to date, weigh the cat, examine the teeth and catch early signs of disease. Ask your vet what suits your cat.

The key tasks are keeping weight steady and keeping the mind busy. Neutered adults are prone to putting on weight, so feed measured portions of a complete and balanced food, see complete and balanced, and offer daily play and climbing opportunities. Indoor cats in particular need enrichment, see enrichment.

Watch for slow changes in appetite, thirst, litter-box habits, activity or weight, since these are often the earliest signals of illness. Tell your vet if you spot any.

Last reviewed November 7, 2026

In the index now

Related terms

Junior cat The life stage from about seven months to two years, when a cat reaches adult size and sexual maturity and its energy peaks. Mature cat A cat of about seven to ten years old, equivalent to a person in their mid-forties to fifties, when screening for age-related disease begins. Senior cat A cat from about 10 or 11 years old, when joint, kidney, thyroid and dental disease become more common and check-ups should be more frequent. Resting energy requirement The calories a resting cat uses each day, a baseline vets multiply by a factor to work out how much food an individual cat needs. Wet food Cat food sold in cans, pouches or trays, containing roughly 70 to 80 percent water, which helps a cat get more fluid.

Related guides

Why a senior cat can be the right cat What adopting an older cat offers, what to ask the shelter, the health costs to plan for, and how to help a senior settle in. Bringing home an adult shelter cat How to prepare for an adult shelter cat, the first days at home, the settling period, the vet visit and the signs that mean a problem.