How to Read Social Signals Between Cats

When introducing a new cat, reading the signals cats are sending matters more than rigidly following the steps — it tells you whether to move forward or pause.

Friendly / Relaxed Signals

A tail held upright with a slight curl at the tip, ears relaxed and forward, slow blinking (a cat's "kiss"), approaching from the side rather than head-on, and mutual grooming are all signs of a stable or even friendly relationship. If both cats can relax and go about their own business in the same space (not just tensely ignoring each other), it's a sign you can move on to the next introduction step.

Tense but Not Yet Aggressive Signals

A lowered body, ears turning slightly back, dilated pupils, forceful tail thumping on the floor, low growling or hissing — these are warning signals meaning a cat feels threatened but isn't planning to act yet. At this stage, the best response is to distract and create distance; there's no need to panic, but don't push them to keep interacting either — go back to the previous introduction step and try again.

Aggressive Signals That Need Immediate Intervention

Fully dilated pupils, an arched, puffed-up body, raised fur, continuous growling or hissing, and direct pouncing or chasing all call for immediate physical separation (throw a cloth over the line of sight, or block their view with cardboard — avoid pulling them apart by hand to prevent accidental injury). Let both cats calm down separately, then go back to an earlier stage where both felt safe.

Reading Signals Matters More Than Following a Rigid Schedule

The AAFP ten-step introduction protocol is a safe framework, but every pair of cats moves at their own pace — some can advance to the next stage within days, others need weeks at the same step. Rather than rigidly advancing on a fixed timeline, it's more important to keep watching the signals both cats are sending: move forward when they stay calm and relaxed, and step back when warning signs appear. Patience matters more than speed.

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This site is for general reference only and is not a substitute for veterinary diagnosis. If your cat shows unusual signs, please see a vet promptly.