Is my cat in pain? Use the Cat Grimace Scale as a clue, not a verdict

Your cat’s poker face could win The Traitors

A cat can look composed while feeling anything but. Cats Protection says cats are particularly good at hiding pain and may show a small lifestyle or behaviour change instead of an obvious limp. That makes “is my cat in pain?” a sensible question—and a risky one to answer from a random photo or a confident app verdict.

The Feline Grimace Scale, often shortened to FGS, is different from an entertainment filter. Researchers developed and validated it to assess acute pain from five changes in a cat’s face. A 2026 systematic review found that it was among the feline tools with the strongest measurement evidence.

Still, a scale is a clue, not a diagnosis. It cannot tell you why a cat is uncomfortable, and a low score cannot declare them fine. The safest home use joins three things: the official scale, what is different from your cat’s normal and a real conversation with your veterinary practice.

Use the real scale, in the right moment

Start with the official Feline Grimace Scale website or its free app rather than a copied social graphic. The instructions ask you to watch your cat undisturbed for 30 seconds. They should be awake and resting; wait if they are sleeping, eating, grooming or vocalising.

Do not wake your cat, hold their head, touch a sore area or keep repeating a movement for the camera. If taking a photograph or short video is safe, the original can help a veterinary team see an intermittent change. Capturing perfect content is never more important than making the call.

Each of the five facial action units is scored zero, one or two. A one also covers uncertainty, which is useful: honest doubt is better evidence than forcing a face into the nearest box.

The five things you are actually looking at

The scale looks at ear position, eye narrowing, muzzle tension, whisker position and head position. In the official examples, a comfortable-looking cat tends to have forward ears, open eyes, a round relaxed muzzle, loose curved whiskers and a head carried above the shoulder line.

As the action units become more marked, the ears may rotate outwards, the eyes narrow, the muzzle looks tenser, the whiskers straighten or move forwards and the head lowers. Coat pattern, face shape, lighting and the viewing angle can make these details hard to judge. Use the official training images and choose “uncertain” when that is the honest answer.

The official scale tells owners to contact their veterinarian when the total is four or more. Do not turn that threshold around: a score below four is not an all-clear, and it is never an instruction to wait when your cat’s behaviour has changed or you are worried.

• Ears: forward and relaxed, or pulled apart and rotated outwards?
• Eyes: normally open, or increasingly narrowed?
• Muzzle: round and relaxed, or flattened and tense?
• Whiskers: loose and curved, or straighter and pushed forwards?
• Head: above the shoulder line, level with it or lowered?

The face is one clue; “different from normal” is the bigger story

International Cat Care says a change in a cat’s normal behaviour tends to be the most significant sign an owner notices at home. That context matters because the Grimace Scale was built for acute pain. It is not a general wellness score, a chronic-pain diagnosis or a way to monitor every sleepy senior face.

Write down what changed and when: food and water actually taken, litter-tray output, jumping or stairs, play, grooming, hiding, sleep position and tolerance of people or other pets. Cats Protection lists reduced eating or drinking, reluctance to jump, stiffness, withdrawal, overgrooming and coat changes among the signs worth discussing with a vet.

A timestamped, factual note is more useful than “she seems sad”. Keep uncertainty visible: “ate about half breakfast” is better than an app silently converting it into a precise percentage.

• What was ordinary for your cat yesterday or last week?
• What changed, and what is the earliest honest time window?
• What did they eat, drink and pass in the litter tray?
• Did jumping, walking, grooming, play, hiding or interaction change?
• What are they doing now, and what do you need the vet to decide?

When to stop observing and call

Contact your veterinary practice if you think your cat may be in pain, their behaviour changes or the official score reaches four. Call even when the number is lower if your knowledge of the cat tells you something is wrong. The practice can decide how quickly they need to be seen.

Seek urgent veterinary help for breathing difficulty, collapse, a seizure, serious trauma, suspected poisoning or a cat who appears severely unwell. Do not delay while searching for a better angle, running another app or asking strangers to score a picture.

Never give paracetamol, ibuprofen or another human painkiller, and never borrow medicine prescribed for a different animal. The official scale explicitly tells owners not to give painkillers without veterinary guidance.

Why this is a cat guide, not a dog-and-cat score

Dog owners often reach the same search from an event—limping after a walk, becoming reluctant to climb stairs or reacting differently to touch. The sensible record is still the change, time, movement and current behaviour, followed by veterinary advice.

But there is no responsible reason to paste the feline facial checklist onto a dog. The 2026 systematic review found that acute-pain instruments for dogs generally had weaker evidence and reporting than the strongest cat instruments. Wiggly should keep the dog observation path separate and avoid inventing a universal pet pain score.

For both species, the product opportunity is the hand-off: preserve what the owner actually noticed and make it easier to share—not convert a photo into a diagnosis or a “safe to wait” badge.

The useful Wiggly tool is an observation note, not a pain camera

Search results now mix the official scale with apps that promise to interpret a cat’s face automatically. Wiggly has a safer lane: a small cat observation note that links to the official FGS training, records the viewing conditions and keeps behaviour changes beside the image or appointment.

A good flow would ask whether the cat was awake and undisturbed, save the owner’s uncertain observations in their own words, prompt for eating, toileting, movement and grooming, and offer a clear route to contact the veterinary practice. It should never automatically score a face, recommend medicine or suppress a call.

That is less theatrical than an AI pain detector. It is also more useful when you are worried: the faithful facts stay together, the guesswork gets banished and the vet keeps the clinical decision.