Cat Hiding Pain: 20% Food Drop, 30 Breaths, FGS

A cat in pain eats 20% less before it looks sick, and a cat in trouble breathes faster than 30 times a minute while it sleeps. Those 2 numbers catch more early disease than any mood change you can spot from across the room. Cats sleep 12-16 hours, hide under furniture when unwell, and purr when frightened, so the signals that hold up are counts: grams eaten, breaths per minute, clumps in the litter box, and 5 facial markers scored 0-2.

Why the mask works

A cat is a 4-5 kg predator that also serves as prey, and showing weakness invites a fight over 1 food bowl and 3 resting spots. The result is a species that eats through mild pain and only stops at severe pain, usually 2-4 days after the problem started. Owners report noticing nothing until the cat stopped jumping on the bed, which is often day 5-7 of a dental or joint problem.

The 20% food rule

Weigh the food, not the bowl. A 4.5 kg cat eating 60 g of dry food a day that drops to 48 g has lost exactly 20%, and that is the line where a vet visit beats waiting. Two consecutive meals refused, or 24 hours with no food at all, is an appointment within 24 hours; 48 hours without food in an overweight cat is an emergency, because hepatic lipidosis can start in 2-4 days.

Weight backs up the food log. Weekly weighing on a baby scale, to 20 g, catches 3-5% loss that a hand on the ribs misses. A 4.5 kg cat that reaches 4.1 kg in 3 weeks has lost 9% and needs bloodwork, including a T4 and a kidney panel, before anyone blames pickiness.

Breathing: count 30 seconds

Count chest movements while the cat sleeps, not while it plays. Thirty seconds multiplied by 2 gives breaths per minute; normal resting rate is 16-30, and asleep it can sit at 15-20. Over 30 at rest is abnormal, over 40 is a same-hour call, and open-mouth breathing at any rate is an emergency in a cat.

Film 10 seconds on a phone when the rate is borderline. A rate that climbs from 24 to 34 across 3 days tracks fluid or inflammation better than one bad reading, and the video gives the vet a baseline that a number in a notebook cannot.

The Feline Grimace Scale: 5 units

The Feline Grimace Scale (FGS) scores 5 action units 0-2 each, for a total of 0-10; a total of 4 or more is the usual trigger for a pain assessment. Score the cat from 30-60 cm away, before you touch it, because handling changes the ears within seconds.

Action unit	0 score	1 score	2 score	What to watch
Ear position	0 ears forward	1 slightly flat	2 flattened out	rotation, not angle
Orbital tightening	0 eyes open	1 partly shut	2 squinting	3-5 mm lid gap
Muzzle tension	0 relaxed	1 mild strain	2 tense	nose to lip line
Whisker position	0 loose, curved	1 partly forward	2 forward, bunched	tip direction
Head position	0 above shoulders	1 level	2 below shoulders	neck angle

Score twice, 2 hours apart, and keep both sheets. A 0 on all 5 units at 08:00 and a 5 at 20:00 is a pattern, and patterns are what get a cat treated on the first visit instead of the third.

Litter box and water

Count clumps for 3 days and you have a urine baseline: 2-3 clumps a day for a cat on wet food, 3-5 on dry. Output below 20 ml per kg per day, or 3 or more trips to the box in 10 minutes with little produced, points at the bladder and needs a same-day call. No urine for 24 hours in a male cat is a blockage emergency, not a behavior problem.

Water intake of 40-60 ml per kg a day is the textbook range, so a 4.5 kg cat drinks 180-270 ml. A cat that suddenly empties a 300 ml bowl twice a day, or stops drinking for 24 hours, needs bloodwork for kidneys, thyroid and glucose.

Coat, smell, and the third eyelid

A well cat grooms 3-5 times a day and keeps the coat smooth from shoulder to tail base. Greasy fur at the tail base, a scruff that stays tented for 2 seconds, or dandruff along the spine tracks 3-5% dehydration and reduced grooming. The third eyelid showing 2-3 mm at rest is a quiet sign of pain, weight loss or dehydration and deserves a same-week exam.

The 7-day log and the call list

Log 6 things daily for 7 days: grams eaten, grams of water, urine clumps, stool count and form on a 1-7 scale, resting breaths, and 1 photo of the face at the same time each day. That sheet turns a vague worry into 3 numbers a vet can act on.

Call the clinic within 24 hours for any of: 20% food drop over 2 days, resting breaths over 30, 5 or more FGS points, 2 litter box misses in 48 hours, or hiding in a new place for 2 days. Go now for open-mouth breathing, a breath rate over 40, no urine for 24 hours, a temperature over 39.5 C, gums that are white or yellow, or a cat that cannot settle in any position. Travel stress that starts before the appointment is its own problem and is covered in /behavior/car-travel-stress-cat/; if pain is turning into bites, read /behavior/cat-aggression-biting/ before the next handling attempt, and use /tools/breed-quiz/ only for breed traits, never as a stand-in for an exam.

Five steps for this week

1. Put a kitchen scale next to the food bin and log grams for 7 days.
2. Count resting breaths for 30 seconds, twice a day, and write the doubled number.
3. Score the 5 FGS units from 30-60 cm before touching the cat, morning and evening.
4. Count urine clumps for 3 days to set a baseline of 2-5.
5. Photograph the face at 09:00 daily; compare day 7 against day 1 before you call.

Frequently asked