Cat Pain Signs: Read the Face and Body Correctly
Quick answer
Check your cat's face, posture, and behavior: squinted eyes, flattened ears, tense muzzle, hunched body, and withdrawal are the main pain signals. A scoring tool called the Feline Grimace Scale lets owners rate each sign from 0 to 2 and get a total score. A score above 0.39 out of 1.0 signals that pain relief is likely needed. Because cats naturally hide discomfort, a structured check beats guessing.
Why Cats Hide Pain and Why That Matters
Cats are prey animals, and showing weakness in the wild invites attack. That instinct does not disappear in a domestic cat. As the Feline Grimace Scale researchers note, pain is often difficult to recognize in cats due to their unique behavior, and cats tend to inhibit the overt expression of pain to avoid appearing vulnerable. Without a structured check, most owners miss it.
Research confirms how hard unaided judgment is. In one study, observers shown photos of painful and pain-free cats could not reliably tell them apart. Only 13 percent of observers could correctly identify more than 80 percent of painful cats. That is why a validated, structured tool matters more than a gut feeling.
The Feline Grimace Scale: A Validated Tool You Can Use at Home
The Feline Grimace Scale (FGS), published in 2019, is the most studied acute pain assessment instrument for cats. It scores five specific facial features, called facial action units (FAUs), on a 0 to 2 scale. It was designed for use by both veterinary professionals and cat owners, including in the home environment. A free app is available (note: the app developer has a commercial interest in promoting the tool).
The Five Facial Action Units to Check
Observe your cat’s face in a calm moment, ideally from a short distance so you do not startle them. Score each of the five features:
- Ear position: Are the ears upright and forward (normal), or rotated outward, flattened, or pinned back?
- Orbital tightening: Are the eyes open and relaxed, or are the eyelids squinted or partially closed?
- Muzzle tension: Is the muzzle soft and rounded, or does it look tense, elongated, or flattened?
- Whisker change: Are whiskers fanned out naturally, or are they pulled back, bunched, or pointing forward stiffly?
- Head position: Is the head held up normally, or is it lowered below the shoulders or tucked down?
Each FAU gets a score: 0 = absent, 1 = moderately present, 2 = obviously present. If one feature cannot be assessed (for example, the cat turns away), mark it as not scorable and exclude it from the total.
Calculating the Score
Add up the scores for all assessable FAUs, then divide by the total possible points for those FAUs. If all five are scorable, the maximum is 10. If one is excluded, the maximum drops to 8.
Illustrative example (checked arithmetic): Suppose your cat scores ear position 1, orbital tightening 2, muzzle tension 1, whisker change 1, head position 1. Total = 6. All five FAUs are scorable, so maximum = 10. Score = 6 divided by 10 = 0.60 out of 1.0.
The validated analgesic threshold is a score above 0.39 out of 1.0. A score at or below 0.39 suggests pain is not detected. A score above 0.39 suggests pain is present and treatment may be needed. This threshold was established through clinical validation studies.
Step-by-Step Pain Check for Cat Owners
- Choose a calm moment. Assess your cat when they are resting quietly, not right after play or a stressful event like a car ride.
- Observe from a short distance first. Watch the face and overall posture before approaching. Approaching too quickly can change the cat’s expression.
- Score each of the five FAUs using the 0 to 2 scale described above. Write the scores down.
- Calculate the total score by dividing the sum by the maximum possible (10 if all five are scorable, 8 if one is excluded, 6 if two are excluded).
- Compare to the threshold. A score above 0.39 out of 1.0 indicates likely pain. Contact your veterinarian.
- Repeat the check if you are unsure. The FGS shows excellent intra-rater reliability, meaning your own repeated scores on the same cat tend to be consistent.
Body Posture and Behavior Clues
The FGS focuses on the face, but posture gives additional context. If you notice changes in normal comfort behaviors like kneading, that shift in routine is worth noting alongside a pain check.
Stop Conditions: When to Call a Vet Right Away
The FGS helps you recognize that something is wrong and that treatment may be needed. It does not replace veterinary diagnosis. Stop home assessment and contact a veterinarian or emergency animal clinic immediately if you observe any of the following:
- Your cat is breathing with visible effort, open-mouth breathing, or making unusual sounds while breathing.
- Your cat is completely unresponsive, collapses, or cannot stand.
- You see a wound, swelling, or obvious injury.
These signs override any home scoring. The WSAVA Global Guidelines for the Recognition, Assessment and Treatment of Pain emphasize that recognizing pain and getting appropriate treatment is central to patient health and welfare. A veterinarian can assess the underlying cause and provide safe, appropriate pain management. Do not give human pain medications to cats; many are toxic to them.
A Common Mistake: Assuming a Quiet Cat Is a Comfortable Cat
Many owners assume that if a cat is not crying or limping dramatically, it is fine. The research behind the FGS shows this is wrong. Cats suppress pain signals as a survival behavior. A cat sitting quietly in a corner with slightly squinted eyes and flattened ears may be in significant discomfort. Using the structured five-point face check, rather than waiting for obvious distress, catches pain earlier. For ongoing care questions, the Cats topic hub covers a range of behavioral and health topics that can help you track changes over time.
Frequently asked questions
Can the Feline Grimace Scale detect chronic pain, or only sudden pain?
The FGS was validated specifically for acute pain in cats. Research on grimace scales across species notes that behavioral changes are mainly observed with acute pain (hours) but are less pronounced in longer-lasting pain. For suspected chronic pain, such as arthritis in a senior cat, a veterinarian should assess the cat directly using additional clinical tools.
How often should I check my cat's pain score if I am worried?
The FGS is designed for real-time or repeated assessment. If your cat had surgery or an injury, checking every few hours is reasonable. The scale shows excellent intra-rater reliability, so your own repeated scores on the same cat tend to be consistent. If the score stays above 0.39 or rises, contact your veterinarian rather than waiting.
My cat growls when I touch one spot but seems fine otherwise. Is that pain?
Combine any reaction you notice with a Feline Grimace Scale face check. If the FGS score is above 0.39 or the reaction is new and consistent, have a veterinarian examine that area to rule out injury, infection, or internal issues.
Does a cat in pain always vocalize or cry?
No. Cats often do not vocalize when in pain. Because they instinctively suppress signs of vulnerability, many cats in significant discomfort remain quiet. Vocalization can occur with severe or sudden pain, but its absence does not mean a cat is comfortable. Facial and postural signs are more reliable indicators than sound alone.
Can I use the FGS app myself, or is it only for vets?
The Feline Grimace Scale app and scoring method are designed for use by both veterinary professionals and cat owners in the home environment. The developers note it can be used by anyone, anywhere. Keep in mind the app developer has a commercial interest in the tool. The underlying scoring method is free and publicly documented in the original research.
Sources
- Feline Grimace Scale | Easy Acute Pain Assessment in Cats · Feline Grimace Scale website (felinegrimacescale.com)
- Pain Guidelines - WSAVA · World Small Animal Veterinary Association (wsava.org)
- Grimace scale - Wikipedia · en.wikipedia.org
Prepared from these references and checked against them. References retrieved October 11, 2026.
Spotted an error? Tell us what needs correcting.