The short answer for a Devon Rex
A Devon Rex typically stops growing in frame — height at the shoulder and length of body — at around twelve months, and finishes filling out over the following few months as muscle and the adult face develop. Individual pace varies: some Devon Rex kittens shoot up early and plateau, while others grow in slow, steady increments right up to their first birthday. Genetics from the parents is the best preview — a kitten from small parents finishes small, and that is healthy, not stunted.
What growth looks like month by month in a Devon
Growth in a Devon Rex kitten is fastest in the first six months, when legs lengthen, the large ears seem to belong to a much bigger cat, and the wavy coat goes through awkward patches as the adult coat comes in. From roughly six to nine months the frame is mostly built and the kitten starts adding condition — a little more chest, a little more substance over the hips — rather than obvious height. Appetite often surges and dips across this phase, and a lean, racy look is normal for an adolescent Devon that burns energy in play. After the first birthday, changes become subtle: the cheeks widen slightly, the body firms, and weight stabilises at its adult level if portions are adjusted from kitten feeding to adult feeding at the right point.
Judging finished size by condition, not comparison
The most common mistake with a Devon Rex is measuring it against unrelated breeds and concluding it has failed to grow. Feel for ribs under a slight covering and a waist that tucks in behind them, and a Devon Rex matching that picture is at a healthy adult weight whatever the scale says.
Feeding the transition from growing to grown
A Devon Rex that has stopped growing needs less food energy than the same cat did at seven months, and the switch from kitten portions to adult portions is where many indoor Devons quietly gain. Keep protein quality high, since a fine-boned, active breed maintains lean muscle on it, and spread meals across the day if your Devon is a grazer by temperament. Fresh water matters through the transition too; a cat that drinks noticeably more than usual for more than a day or two should be seen by the vet rather than simply topped up.
When slow growth is worth a vet visit
Ask a vet about a Devon Rex kitten's growth if it falls visibly behind littermates week after week, loses weight at any point, or reaches six months still looking like a much younger kitten. Growth that stalls alongside loose stools, a dull or patchy coat beyond the normal kitten coat change, low energy, or a swollen-looking belly needs a prompt appointment rather than watchful waiting. Equally, a young Devon that seems to finish growing very early and then gains only fat should be checked, because portion changes and health checks are easier at eight months than after a year of habit. Bring dates and weights if you have them — a written growth trail turns a vague worry into something the vet can judge in one visit.
Keeping the growth record in one place
A Devon Rex's growth story is scattered by nature: breeder weights from the first weeks, vaccination-visit weights at the clinic, and your own home weigh-ins in between. Assembling those figures into one continuous record is what lets a vet spot a plateau or a surge at a glance. A KinsLe Pet Passport holds those weigh-ins alongside the rest of the cat's records in a single portable packet, so the Devon Rex's path from tiny kitten to finished adult is documented rather than reconstructed from memory.