Puberty is the usual explanation
When an adolescent kitten who was litter-trained suddenly begins backing up to furniture, tail quivering, and spraying a small amount of strong-smelling urine onto vertical surfaces, the most common explanation is that sexual maturity has arrived. Spraying is a scent advertisement rather than a toilet accident: it announces presence and status to other cats, and the behaviour typically appears as hormones rise during adolescence. It is seen most often and most intensely in unneutered males, but females and neutered cats can spray too, particularly when something in their territory feels unsettled. The timing is your first clue: marking that begins exactly as a kitten matures is usually hormonal, while marking that begins after a house move, a new pet or building work outside the window often has a stress component.
Tell spraying apart from a litter problem
The distinction matters because the causes and the vet conversation differ. A spraying cat stands, backs toward a vertical target such as a chair leg, wall or curtain, lifts a trembling tail and releases a small amount, then usually walks away without digging or covering. A cat with a litter or physical problem instead squats and urinates on horizontal surfaces, often visiting the box frequently, passing small amounts, or avoiding the box because using it has become uncomfortable. Watch which pattern you are seeing, where it happens, and how often, and write it down while it is fresh, because those details are the most useful thing you can hand your veterinarian.
What to discuss at the appointment
Go in with four topics ready. First, neutering: if your kitten is not yet neutered, ask about timing, because neutering before or soon after spraying becomes established greatly reduces hormonally driven marking in most cats, and your vet can advise what suits his age and health. Second, a physical check: mention the pattern you recorded and ask whether a urine sample or examination is worthwhile to rule out urinary discomfort contributing to the behaviour. Third, stress: describe any recent changes at home, neighbourhood cats visible through windows, or conflict with another pet, and ask about environmental adjustments. Fourth, cleaning and management at home while you work on causes, including how to clean marked spots so the scent does not invite a repeat performance.
Signs that should not wait for a routine visit
Most adolescent spraying is a behaviour conversation, but some urinary signs are urgent in any cat and especially in males. Contact a veterinarian promptly, the same day, if your kitten strains in the litter box and produces little or nothing, cries while trying to urinate, visits the box constantly, licks at himself excessively, becomes lethargic, or if you see blood in the urine. A male cat who cannot pass urine is an emergency, not a marking problem, and needs immediate care. Book a routine appointment without delay if marking is accompanied by appetite change, weight loss or a clear change in his usual temperament.
At home while you work on the cause
Clean marked furniture and walls thoroughly with a cleaner made for pet urine so no scent residue remains to draw him back, keep litter boxes clean and plentiful in quiet locations, and try not to punish him, since spraying is communication rather than disobedience and punishment adds stress to a behaviour stress can drive. If an outdoor cat is the trigger, blocking the view at the favourite window sometimes lowers the temperature of the whole problem while neutering and time do their work.
Bringing organised notes makes that vet discussion far more productive, and KinsLe's Pet Passport keeps your record of when the marking started, where it happens and what changed at home alongside his vaccination and visit history in one place.