The short answer: at least once a year for a healthy adult
For an adult cat in good health, a full check once a year is the standard rhythm most practices work to, usually combined with vaccination boosters so the trip serves two purposes. That interval is a compromise between what is practical for owners and how quickly the common feline problems develop. Dental disease can progress from mild tartar to painful teeth within a year, a slow weight gain can become entrenched, and early kidney or thyroid changes in a middle-aged cat may be developing silently while she still looks bright. An annual hands-on examination is the safety net that catches those shifts while they are still small, cheap to address and unlikely to have caused lasting harm.
Cats are unusually good at concealing illness. A cat who is eating a little less, sleeping a little more and playing a little less rarely looks ill in any single week; the change only shows when a vet weighs her, feels her body condition and compares this year against last year's notes.
When once a year is not often enough
As cats move into their senior years, most vets suggest checks twice a year, because the conditions of old age can move faster and a six-month gap catches change earlier. The same applies at any age to cats living with an ongoing issue the clinic is managing, such as a heart murmur being monitored, previous urinary trouble, or a weight problem under active review — your vet will set the interval for your cat rather than following the calendar alone. Kittens sit at the other end of the scale, seen several times in their first months, and a newly adopted adult cat should have an early check after arriving home regardless of when the last one happened, so your own practice holds a baseline.
What the annual check is actually buying you
A routine adult check is more than a quick glance. The vet weighs your cat and scores body condition, examines teeth and gums, looks in ears and eyes, listens to heart and lungs, feels the abdomen, joints and lymph nodes, and checks coat and skin for parasites, lumps or sore patches. You will be asked about appetite, drinking, litter habits, behaviour and activity, and those answers steer what the vet looks at hardest. Vaccination status and parasite prevention are reviewed against your cat's real lifestyle — an indoor-only cat and a roaming hunter do not carry identical risks. For older cats the vet may suggest blood or urine screening alongside the physical exam, since laboratory results can reveal change before hands and eyes can.
Do not let the calendar overrule your eyes
The annual rhythm assumes a well cat. Book sooner, whatever the date, if you notice your cat drinking or urinating noticeably more, losing weight while eating normally, going off food for more than a brief spell, breathing differently, straining in the litter tray, developing a lump, or behaving out of character — hiding, vocalising at night, or stopping grooming. Between appointments, your part of the system is observation: monthly home weighing, a feel over the ribs, a look at the teeth when your cat yawns, and a note of anything that changes. Owners who arrive able to say when a change started give the vet a running start.
Make each visit build on the last
A health check is worth most when it is compared against the previous ones, which depends on records being complete and findable. Bring your notes on weight, appetite and any episodes since the last visit, and keep the clinic's findings, vaccination entries and screening results filed together afterwards rather than scattered through drawers and message threads. Stored as one continuous record in KinsLe's Pet Passport, those annual snapshots let any vet see your cat's weight line, dental history and past results at a glance — and that comparison across years is where a routine check earns its keep.