Cat Pain Detection Guide: How to Spot Discomfort Early

Why Do Cats Hide Pain?

Cats’ ancestors were solitary predators that were also prey for larger animals. In that environment, showing weakness meant exposing yourself as an easy target. Even though domestic cats now live safely, the instinct remains.

This means cats won’t howl or whine like dogs do when in pain. Mild to moderate pain often shows no obvious behavioral changes. By the time a cat is obviously hiding, not eating, or not drinking, the situation may already need urgent attention. That’s why the subtle signs matter.

There are two flavors of pain to learn to spot, and they look different:

• Acute pain is sudden onset, often from injury, surgery, or illness. The Feline Grimace Scale below is the validated tool for this.
• Chronic pain builds slowly over months or years. Most often it’s arthritis in an older cat. The Grimace Scale was not designed for chronic pain; you need a different lens.

The Feline Grimace Scale (Acute Pain)

In 2019, researchers at the University of Montreal published the Feline Grimace Scale, a tool for assessing acute pain in cats based on facial expression. It has been validated in clinical studies, and owners can learn it without medical training. The scale scores five facial features (ears, tightening around the eyes, muzzle tension, whisker position, head position) from 0 to 2 each, for a total out of 10.

Use the interactive tool below to assess your cat. Score each of the 5 facial features from 0 to 2 based on what you observe:

Pain Assessment Tool

Select a score for each feature based on your cat's current expression

1

Ear Position

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0

Forward, upright

1

Slightly rotated outward

2

Flattened outward and back

2

Eye Squint

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0

Eyes open

1

Partially squinted

2

Markedly squinted

3

Whisker Tension

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0

Relaxed, hanging down

1

Slightly forward

2

Stiff and forward

4

Muzzle Shape

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0

Relaxed and round

1

Slightly tense

2

Tense and oval

5

Head Position

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0

Above shoulder line

1

Level with shoulders

2

Below shoulder line

0

Total Score (out of 10)

Likely no obvious pain

Continue monitoring your cat's behavior regularly.

Reset

A score of 4 or above suggests the cat may be experiencing acute pain and should be evaluated by a veterinarian. Higher scores mean more confidence that pain is present, not necessarily that the pain is worse.

How to Assess Correctly

Pick a time when your cat is awake but resting quietly. Avoid scoring right after waking, eating, grooming, vocalizing, or during play. Look at the overall picture rather than fixating on one feature. Knowing your cat’s normal baseline expression matters; some cats simply have a slightly squinted resting face.

Common mistakes: confusing sleepy eyes for pain squinting, and scoring after a single quick look. Observe at multiple moments before drawing a conclusion. If you’re not sure, take a clear, well-lit photo and reassess later.

When the Grimace Scale Doesn’t Apply

The Grimace Scale was designed and validated for awake, alert, naturally-occurring acute pain. It is not reliable in several situations:

• A sleeping cat. Closed eyes during sleep are not pain squinting. Wait until your cat is awake and at rest.
• A heavily sedated cat or one recovering from anesthesia. Sedation changes facial muscle tone independently of pain.
• A cat wearing an e-collar or recovery cone. The cone changes head position and partially obscures the face.
• Brachycephalic (flat-faced) breeds, including Persians, Exotic Shorthairs, and British Shorthairs. Their baseline muzzle and ear positions differ from the cats in the original validation set, and recent work suggests pain can be overestimated by image-based scoring in these breeds. The scale can still be useful for these cats, but compare against your own cat’s usual face and treat the reference photos as a rough guide.
• Sphynx, Devon Rex, and other cats with very sparse or curly whiskers. The whisker action unit is hard to score reliably. Weight the other four features more heavily.
• Senior cats with cognitive dysfunction. Baseline facial expression may be altered by the disease itself, not pain.

In any of these situations, lean more on behavioral signs and on a vet exam.

Other Pain Signs Worth Watching

Facial expression is the most validated cue, but behavior gives you a second channel that often catches what the face misses, especially in cats whose face is hard to score.

Movement and activity. Fewer or smaller jumps, hesitation before jumping (the cat measures twice), an altered gait, holding a paw up, stiffness on rising, lying down more than usual. A cat that used to leap onto the kitchen counter and now hops onto a chair first is telling you something.

Daily routine. Decreased appetite, drinking changes, altered litter box behavior, reduced or excessive grooming, grooming only certain areas, or unkempt fur on parts of the body that used to be well-kept.

Social and behavior. Hiding more often, reduced interest in interaction, withdrawal from family routines, new aggression when touched (especially in a specific spot), flinching, or reluctance to be picked up the way they used to be.

Sound. Many cats stay quiet when in pain. Vocalization is unreliable as a pain signal; absence of vocalization does not mean absence of pain. A previously quiet cat who is suddenly yowling, especially at night, deserves a vet check.

Reading body posture and behavior together is the same skill as reading mood: the question is always whether this is unusual for this cat.

Chronic Pain in Senior Cats

If your cat is over about 7 years old, chronic pain becomes the more common problem, and it is dramatically under-diagnosed.

Radiographic studies of older cats find degenerative joint disease in the majority of them. One often-cited finding is that around 90% of cats over 12 years old have radiographic evidence of degenerative joint disease, and a more recent estimate found radiographic signs of osteoarthritis in roughly 60% of cats over 6 years. Most of those cats have never been diagnosed. Their owners describe them as “slowing down with age” when what is actually happening is osteoarthritis pain.

Cats with arthritis on both sides usually don’t limp. Limping requires one good leg and one painful leg to favor it. When both hips, both elbows, or both stifles are hurting, the cat just moves less. They jump less, climb less, groom less, play less. The signal looks like aging, not injury, which is why it slips past so many owners.

What to watch for instead of limping:

• Hesitation before jumping up onto furniture, or breaking the jump into two stages
• Avoiding stairs, or going up/down one at a time
• Reduced grooming, especially the back, base of tail, and rear legs (these are hardest to reach with stiff joints), leading to matted or greasy fur
• Sleeping more in a single chosen spot rather than circulating around the house
• Reluctance to be picked up or to have hindquarters touched
• Litter box accidents, especially in cats who used to be reliable, because high-sided boxes hurt to climb into
• Subtle personality changes: less interactive, less playful, more irritable when handled
• A slightly hunched standing posture, or sitting with weight shifted off a particular limb

A useful at-home tool is the Feline Musculoskeletal Pain Index (FMPI), a questionnaire developed for owners to track their cat’s mobility and activity over time. It is not a diagnosis on its own, but bringing a completed FMPI to a vet visit gives the vet specific information they can act on. Your vet may also use clinical orthopedic exams and, when needed, radiographs.

If you have a senior cat and have never raised the possibility of arthritis with your vet, raise it. Treatment options have improved a lot in the last few years.

Pain Medication Comes from Your Vet

There are pain medications made for cats, for both acute pain and chronic arthritis, including a newer once-a-month injection for feline arthritis. All of them need a vet to assess your cat and set the dose, often after bloodwork, so don’t reach for anything at home.

Supplements like glucosamine and omega-3 fatty acids have a place in the longer-term plan, but they are slower-acting and do not replace pain relief for a cat in active discomfort.

When to See a Vet

Move to a vet visit if you see any of the following:

• Feline Grimace Scale score of 4 or above
• Pain signs that persist more than 24 hours
• Other symptoms appearing at the same time, especially not eating, not drinking, vomiting, or diarrhea
• Limping, stiffness, or refusing to move
• A strong reaction when touching a specific area
• Any senior cat with reduced jumping, grooming, or activity that has been creeping in gradually
• Any suspected human-medication exposure, no matter how minor it seems

Cats hide pain by design, which means your job is to look harder than the cat is hiding. Score them when something seems off, watch the behavioral picture over time, and if the answer points toward pain, do not wait it out or improvise at home.

How Furwise Can Help

Chronic pain is caught early by noticing patterns, not single moments. Each small change is easy to dismiss on its own; comparing a few weeks of notes is what gives it away. Logging your cat’s changes in Furwise means you don’t have to rely on memory at the vet. If you suspect acute pain, you can also take a photo of your cat’s face in the app and get a Feline Grimace Scale score.

Frequently Asked Questions

How do I know if my cat is in pain? Watch for facial signs (squinted eyes, ears pulled apart and rotated outward, tense whiskers, a tense muzzle, a lowered head) and behavioral signs (hiding, not eating, less jumping, reduced grooming, flinching when touched). The Feline Grimace Scale scores the facial features 0 to 2 each; a total of 4 or higher suggests acute pain. In older cats, watch for a drop in overall activity: arthritis on both sides usually doesn’t produce a visible limp.

Can I give my cat Tylenol, ibuprofen, aspirin, or other human painkillers? No. Acetaminophen (Tylenol, paracetamol) is rapidly toxic to cats because they lack a key enzyme that humans use to metabolize it; even one tablet can be fatal. Ibuprofen and naproxen cause acute kidney injury and stomach bleeding at small doses. Aspirin has a narrow feline-specific dose and is rarely used at home. If your cat is in pain, call a vet for safe, feline-specific options.

How do I know if my cat has arthritis? Look for slow, gradual changes: smaller or fewer jumps, hesitation before jumping, avoiding stairs, less grooming (especially of the back and tail base), matted or greasy fur, sleeping more in one place, irritability when handled, and litter box accidents. Arthritis usually affects both sides, so most cats slow down without limping. If your cat is over about 7 years old, it is worth bringing up with your vet.

What painkillers can a vet prescribe for cats? There are cat-specific pain medications for both acute pain and chronic arthritis, including a newer once-a-month injection for feline arthritis. Which one and what dose depends on a vet exam and sometimes bloodwork. Never give your cat human painkillers at home.

Do cats limp when they are in pain? Sometimes, but not always. A cat with a single painful leg may limp because the other three legs can pick up the load. A cat with arthritis in both hips or both knees usually does not limp, because there is no good leg to favor. Instead, they jump less, climb less, slow down, and stop grooming hard-to-reach areas. Owners often miss this because it looks like normal aging.

Why does my cat purr when they are sick? Purring is not a reliable “happy” signal. Cats also purr when frightened, in pain, and during illness or end-of-life states, and one idea is that purring may be self-soothing. So a purring cat that is also hiding, not eating, or scoring high on the Grimace Scale should still be treated as a cat in pain.

What is the Feline Grimace Scale, and when should I not use it? The Feline Grimace Scale is a validated tool developed in 2019 for assessing acute pain in cats by scoring five facial features. Do not use it on a sleeping, sedated, or cone-wearing cat. Use it cautiously with brachycephalic breeds (Persian, Exotic Shorthair) and with sparse-whiskered breeds (Sphynx, Devon Rex). It was not designed for chronic arthritis pain; for that, use behavioral signs over time and consider the FMPI questionnaire.

Can cats cry tears from pain? No. Cats do not cry emotional tears from pain the way humans can. Watery eyes in a cat usually indicate eye irritation, infection, or upper respiratory issues, not pain elsewhere. Some cats may vocalize when in acute pain (yowl, hiss, growl), but many stay completely silent. Facial expression and behavior are more reliable cues than tears or sound.