Cat Grimace Scale: 5 Facial Signs Your Cat Is in Pain (2026)

A cat in pain often still eats, still purrs, and still shows up at the food bowl. What changes first is the face. Ears drift apart, eyes narrow, and the whiskers straighten out. The cat grimace scale, known in veterinary medicine as the Feline Grimace Scale (FGS), turns those small changes into a score from 0 to 10. This guide includes the scoring chart and walks you through using it at home. It also explains what a score of 4 or higher means for your next call to the vet.

What Is the Cat Grimace Scale?

The Feline Grimace Scale is a validated tool that measures acute pain in cats by scoring five changes in facial expression: ear position, orbital tightening, muzzle tension, whisker position, and head position. Each one is scored 0, 1, or 2, for a total out of 10. A total of 4 or more suggests the cat needs pain relief.

Who Developed It, and What the 2019 Study Found

The scale came out of Dr. Paulo Steagall's lab at the Université de Montréal. The team published it in Scientific Reports in 2019, and Steagall introduced it to US veterinarians at the AVMA Convention that same year.

The researchers filmed 55 cats undisturbed in their cages: 35 client-owned cats with real, naturally occurring pain and 20 healthy cats as a comparison group. The cats in pain were filmed again after they got pain medication. Their faces relaxed, and their scores dropped.

The results were strong for a quick visual check:

1. 1. Accuracy: the scale picked out painful cats 90.7% of the time and correctly cleared pain-free cats 86.6% of the time.
2. 2. Consistency: four separate observers gave closely matching scores (an inter-rater reliability of 0.89).
3. 3. Agreement with other tools: FGS scores tracked very closely with an older, longer feline pain scale.

The American Animal Hospital Association's 2022 Pain Management Guidelines for Dogs and Cats also list the FGS among the tools vets can use to assess pain in cats.

What It Measures, and What It Doesn't

Here is the part most guides skip. The FGS was built for acute pain, which is pain that comes on suddenly. Think of recovery after surgery, a painful injury, a medical problem, or dental pain.

Slow, long-lasting pain such as arthritis is a different story. Cats adapt to it gradually, and their faces may not show it. We cover the right tool for chronic pain further down.

Cat Grimace Scale Chart: The 5 Facial Action Units

Researchers call each facial feature an "action unit." Use this chart while you look at your cat. A score of 1 also covers the moments when you honestly can't tell.

The five facial action units of the Feline Grimace Scale, each scored 0 to 2.

1. Ear Position

A comfortable cat's ears point forward. As pain builds, the ears pull apart and rotate outward until they look flat and wide, almost like airplane wings.

2. Orbital Tightening (Eyes)

Watch the space between the upper and lower eyelids. In the original study, a score of 2 meant the eyelid gap was less than half the width of the eye. That's a true squint, not the slow, sleepy blink of a content cat.

Narrowed eyes and outward-rotated ears are two of the clearest facial signs of pain in cats.

3. Muzzle Tension

The muzzle is the area around the nose and whisker pads. Relaxed, it looks round and soft. In pain, it stretches into a tighter, elliptical shape. This is the trickiest feature for owners to read, so take your time with it.

4. Whisker Position

Relaxed whiskers hang loose and curve gently downward. Pain straightens them, and in strong cases they point forward or stand out stiffly.

5. Head Position

Picture a line along the top of your cat's shoulders. A comfortable cat holds its head above that line. A hurting cat often lets the head sink level with the shoulders, or below them with the chin tipped down.

How to Score Your Cat Step by Step

You don't need special equipment. You need a calm cat, good light, and a few quiet minutes.

When to Observe, and When Not To

1. 1. Watch without touching. The research cats were filmed alone and undisturbed. Petting, picking up, or calling your cat changes its face.
2. 2. Skip sleeping, grooming, and vocal moments. The study only used images of cats that were not asleep, grooming, or meowing, because those activities change the face on their own.
3. 3. Get a clear front or side view. Use natural light where you can. A photo on your phone lets you zoom in and score it calmly afterward.
4. 4. Score all five features. Give each one a 0, 1, or 2 using the chart above.
5. 5. Write down the total and the time. One score is a snapshot. Several scores over a day show you which direction things are moving.

A quick phone photo lets you zoom in and score each facial feature calmly.

Adding Up the Score: What 4 Out of 10 Means

Add the five numbers together. Here's a worked example:

A total of 5 is above the threshold of 4 that the Université de Montréal team set for pain relief. That cat needs a call to the vet today.

A score of 0 to 3 doesn't promise your cat is fine. It just means the face isn't showing clear acute pain right now. If your cat is also hiding, limping, or off its food, those behavior signs of pain in pets still matter.

Can Cat Owners Really Use the Grimace Scale?

Yes, and there's solid data behind that answer.

In 2021, the Steagall team ran an online survey of 1,262 cat caregivers from 66 countries. None were vets or veterinary students. Each person scored ten images of cats, and the results were compared with scores from experienced veterinarians. The study was published in the Journal of Feline Medicine and Surgery in 2023.

Here's what it showed:

1. 1. Owners were reliable on the total score. Agreement on the total FGS score was rated good (0.65).
2. 2. Eyes and ears were the easiest features. They had the highest agreement among owners.
3. 3. Whiskers and head position were the hardest. Agreement on those two dropped to about 0.37 and 0.38.
4. 4. Muzzle tension was the one feature where owner scores differed noticeably from the vets' scores.
5. 5. Background didn't matter. Age, gender, and country made no real difference to how well people scored.

A separate 2020 study of 24 cats having dental extractions found the FGS stayed reliable in that setting too. Having the owner in the room did not change the cats' scores. If your cat has just had dental work, see our guide to dental care at home as well.

7 Scoring Mistakes to Avoid

1. 1. Scoring a sleeping cat. Closed eyes in sleep are not orbital tightening.
2. 2. Scoring mid-groom or mid-meow. Licking and vocalizing pull the muzzle and ears out of position.
3. 3. Scoring while handling. A cat in your arms is reacting to you, not showing its resting face.
4. 4. Scoring once and stopping. Pain changes over hours. Score at least twice so you can see the trend.
5. 5. Never scoring a healthy day. Score your cat while it's well. Every face is a little different, and a baseline helps you spot real change.
6. 6. Using it for arthritis. The FGS targets acute pain. A low score does not rule out chronic joint pain.
7. 7. Treating the number as a diagnosis. A high score tells you that your cat probably hurts, not why.

Stress can also tighten a cat's face. If your cat recently moved house or met a new pet, read our guide on how to tell stress or illness apart.

Grimace Scale vs. Chronic Pain: Why Arthritis Needs a Different Tool

Chronic pain is extremely common in cats and very easy to miss. In a 2010 study published in Veterinary Surgery, Dr. Duncan Lascelles and colleagues X-rayed 100 randomly selected cats. They found degenerative joint disease in 92% of them.

Because arthritis creeps in slowly, a cat's face may stay calm while its habits change. That's why vets lean on different tools for long-term pain.

Chronic joint pain often shows up as changed habits, like hesitating before a jump, rather than in the face.

If your senior cat has stopped jumping onto the counter, ask your vet about the FMPI rather than relying on the grimace scale.

What to Do If Your Cat Scores 4 or Higher

1. 1. Call your vet the same day and share the score, the time, and what you saw.
2. 2. Take a photo or short video for your vet. Facial changes can fade the moment your cat gets to the clinic.
3. 3. Score again after treatment. In the original study, scores dropped once cats got pain relief. A falling score is good news.
4. 4. Go to an emergency clinic right away if you also see labored breathing, collapse, or straining to pee with nothing coming out. Our guide on when to see the vet covers more red flags.

Never Give Human Painkillers

FAQ

Conclusion

Your cat's face is one of the most honest pain signals you have. Learn the five features, score your cat when it's calm and awake, and treat 4 out of 10 as your cue to call the vet. Keep in mind what the tool can't do: it won't catch slow arthritis, and it can't explain why your cat hurts. Used well, the cat grimace scale helps a cat get help hours or even days sooner.

Have you tried scoring your cat with the grimace scale? Share your experience in the comments, and send this chart to a fellow cat owner who'd want it on hand.