Cats don’t show pain the way we expect. No limping, no crying — often just small, easy-to-miss changes.

That’s why researchers at the University of Montreal developed the Feline Grimace Scale (FGS) — a practical, science-backed way to spot pain just by looking at your cat’s face.

What is the Feline Grimace Scale?

The Feline Grimace Scale (FGS) is a validated tool used to assess acute pain in cats based on facial expressions.

It works by observing small, measurable changes in a cat’s face — things most people wouldn’t consciously notice — and turning them into a clear score.

It’s evidence-based (developed through years of clinical research)
It’s fast and easy to use
It works for both vets and cat owners
It’s even available as a mobile app

In short: it helps answer the question “Is my cat in pain?”

Why this matters

Cats are wired to hide discomfort. By the time pain becomes obvious, it’s often already advanced.

The FGS helps:

Detect pain earlier
Make better treatment decisions
Monitor whether pain medication is working
Improve overall cat welfare

How it works (simple version)

The scale looks at 5 facial features, called “action units”:

Ears
Eyes (orbital tightening)
Muzzle (mouth area)
Whiskers
Head position

Each one is scored from 0 to 2 depending on how different it looks from normal.

0 = looks normal
1 = slightly different / unsure
2 = clearly different

You then add everything up for a total score out of 10.

What different scores mean

0–3 → No or mild pain
4 or more → Pain likely

👉 For pet owners: If your cat scores 4 or higher, you should contact your veterinarian. If you don’t have one or need a trusted option, you can find trusted vets near you on Pet Pro Booking..

👉 Important: Never give human or animal pain medication without veterinary advice.

What pain can look like (in real life)

Here’s how those facial changes typically appear:

No pain (score 0)

Ears facing forward
Eyes open
Face relaxed
Whiskers loose
Head upright

Moderate pain (score 1)

Ears slightly turned outward
Eyes partially closed
Slight tension in face
Head level with shoulders

Severe pain (score 2)

Ears flattened
Eyes squinting
Tight, tense muzzle
Whiskers pushed forward
Head lowered or tilted down

These changes are subtle — but once you know them, you start noticing them everywhere.

How to use it properly

To get an accurate score: Observe your cat quietly for about 30 seconds

Make sure they are:

Not sleeping
Not grooming
Not eating or vocalizing

Then score each facial feature.

💡 Tip: The official app can guide you step by step.

Is it reliable?

Yes — the FGS is one of the most scientifically studied pain assessment tools for cats.

Research has shown it is:

Accurate (measures real pain)
Consistent (different people get similar scores)
Reliable over time
Sensitive to treatment (scores drop after pain relief)

For pet professionals

The FGS is particularly useful in:

Post-surgery monitoring
Hospitalization
Emergency care
Pain management protocols

It provides a standardized way to communicate pain levels across teams and improves clinical decision-making.

For cat owners

You don’t need medical training to use it.

The FGS helps you:

Recognize subtle signs something is wrong
Advocate for your cat at the vet
Monitor recovery at home

Think of it as a “pain detection tool” in your pocket.

Final takeaway

Cats rarely show pain in obvious ways — but their faces do.

The Feline Grimace Scale gives you a clear, science-backed way to read those signals and act early.

Because when it comes to pain: You can only treat what you can recognize.

👉 If you’re unsure whether your cat’s behavior is normal, it’s always safest to check with a professional. You can find and compare trusted veterinarians on Pet Pro Booking.

Resources:

FGS App link + Training manual + Fact sheet