A cat that walked normally an hour ago and now holds one paw off the floor needs a grade before it needs a diagnosis. Sudden limping sorts into 4 weight-bearing grades, and the grade plus the clock decides whether you watch at home for 24 hours or drive to a clinic tonight. Grade 1 or 2 with a temperature under 39.5 C can usually be watched for 24 to 48 hours. Grade 3, grade 4, or any limp that began within 48 hours of a fall from 1.5 m or higher is a same-day visit.
Grade the limp in 60 seconds: the 4-level scale
Watch the cat walk 3 m away and back on a non-slip floor, then stand still 10 seconds. Grade the paw, not the drama. A cat that puts 90 percent of its weight on the leg and trots is a different patient from one that touches the floor for half a second and sits down.
| Grade | Weight on the sore leg | Paw contact | Speed on a 3 m walk | Act within |
|---|---|---|---|---|
| 1 | 80 to 90 percent | Flat, full pad | 4 to 5 s | 48 hours |
| 2 | 60 to 80 percent | Full, toe-first | 6 to 8 s, slight head bob | 24 hours |
| 3 | 20 to 60 percent | Toes only, 1 to 2 s of contact | 10 to 14 s, sits after 5 m | 12 hours |
| 4 | 0 percent | None, leg carried | Hop on 3 legs, 15 s or more | 1 to 2 hours |
A grade 1 cat that eats, uses the litter box and still jumps onto a 40 cm sofa can be watched. A grade 2 cat that stops jumping and hides for 3 hours is a 24-hour case even though the paw still reaches the floor.
Why 24 hours is the first decision point
A strain or a bruise improves measurably inside 24 hours: the cat puts 10 to 20 percent more weight on the leg, walks 1 to 2 m further before sitting, and carpal swelling drops 2 to 4 mm. When none of that happens by hour 24, or the cat is worse at hour 24 than at hour 2, the list moves from soft tissue to infection, fracture or a bite abscess. Take 3 photos at hour 0, 12 and 24 from 1.5 m away, since a strip shows a 1 cm change memory smooths over.
48 hours after a jump or a fall
Cats hide falls well. A jump down from a 2 m shelf, a slip off a 1.8 m wardrobe or a 1 m drop onto tile can crack a metacarpal or bruise a growth plate without breaking skin, and the cat often walks almost normally for 24 to 48 hours on habit and adrenaline. Swelling after a fall usually peaks between hour 36 and hour 48, which is why a cat that starts limping 2 days after a jump gets radiographs rather than a wait. A 1 to 2 mm hairline fracture often needs 2 views at 90 degrees to show at all. A cat that fell over 3 floors, or breathes fast 12 hours after, goes to an emergency clinic regardless of grade.
Five checks that take 5 minutes
- Paw pads and claws: count 5 pads and 5 claws on the sore foot. Look for a 2 mm cut, a claw torn at the base, a 3 mm splinter between pads, or a nail curled into the pad of an old cat.
- Joints: compare left to right at carpus, elbow and hock. Heat plus a 5 mm difference in circumference means more than a cat that pulls the leg away.
- Toes and nerves: pinch 1 toe and count. A normal cat pulls the limb back within 1 second; a delay of 3 to 5 seconds points to nerve or spinal involvement, not a sore paw.
- Skin and fur: part the fur over 10 cm of the leg. Look for 2 puncture wounds 5 to 10 mm apart, a 1 cm scab, or a ring of missing fur.
- Temperature: 38.1 to 39.2 C is normal, 39.5 C and above changes the plan, and below 37.5 C is an emergency because a cold cat with a limp may be shutting down rather than sore.
When the leg is not the problem
Aortic thromboembolism is the limp that kills, and it has its own track in sudden collapse. A cold foot, no femoral pulse on 1 side and a limb that is dragged rather than carried mean a 6-hour window before muscle damage becomes permanent, so that picture is an emergency even at grade 2. Abdominal pain also fakes a limp: a cat with a 1 cm arched spine that refuses to jump but lets you flex every toe without complaint may have pancreatitis or a foreign body. Lameness moving from leg to leg over 48 hours points to immune-mediated polyarthritis. A limp with a 40 C fever or a 24-hour appetite strike is infection until proven otherwise, and a limp after chewing a houseplant belongs in the household poison list first.
Measure the leg, not the mood
Wrap a soft tape at 3 marks: 2 cm above the paw, mid-forearm, and 1 cm below the elbow. Write millimeters, not centimeters, and read each spot twice. A change of 5 mm or more in 24 hours is real swelling; a 2 to 3 mm wobble is usually the tape sitting differently. Dot the 3 spots so tomorrow lands in the same place.
When to see a vet
Call an emergency clinic within 1 to 2 hours for grade 4, a cold or blue foot, a limb dragged with no pulse, breathing over 60 breaths a minute, collapse, or a fall from 1.5 m or higher. Book within 6 hours for grade 3, a wound that punctures skin, a fever at or above 39.5 C, or 12 hours without food. Book within 12 to 24 hours for grade 2 unchanged at hour 24, a joint still hot after 5 seconds of contact, or a limp in a kitten under 6 months. Book within 48 hours for grade 1 that is not improving, or a first limp in a cat over 10 years old; arthritis and bone tumor both start this way. A 15-second walk video often replaces the first recheck.
Family record sheet: 7 lines a day
- Time, 3 times a day at 08:00, 14:00 and 21:00.
- Grade 1 to 4, plus which leg and which paw.
- Circumference in mm at the same 3 marks, same tape.
- Appetite as a percentage of the usual portion, and water in ml if the bowl sits on a scale.
- Litter box visits, urine clumps counted, stool in the last 24 hours yes or no.
- Temperature to 0.1 C, only if the cat tolerates it.
- A 15-second walk video, same corridor and light.
Five steps for today
- Grade the walk and write the number with the time; a grade without a timestamp cannot be compared.
- Do the 5 checks, starting with the paw: many sudden limps start at a claw, not the joint.
- Measure 3 circumferences in mm, photograph the tape, repeat in 24 hours at the same clock time.
- Take a temperature; 39.5 C or higher moves a grade 1 cat into the 6-hour group.
- Set the 24-hour and 48-hour reminders now, and save the clinic number.
Terms mentioned in this article
Frequently asked
My cat limps but still jumps on the bed. Do I need a vet today?
Not always. A grade 1 or 2 limp with a normal temperature, normal appetite and normal litter box use can be watched for 24 hours while you measure joint circumference in millimeters. Book a visit if the grade is unchanged at hour 24, if the joint is hot to touch after 5 seconds, or if the cat stops jumping and starts hiding for 3 hours at a time.
How long after a fall can a limp appear?
A limp can start 24 to 48 hours after a jump or fall, because swelling peaks between hour 36 and hour 48 and cats mask pain well in the first day. A cat that begins limping 2 days after a 2 m drop should have radiographs, with at least 2 views at 90 degrees, rather than another week of rest.
What makes a sudden limp an emergency?
A carried leg at grade 4, a foot that feels cold or looks blue, a limb that is dragged with no femoral pulse on 1 side, breathing over 60 breaths a minute, or a fall from 1.5 m or higher. Those signs carry a 6-hour window before damage becomes permanent, so call an emergency clinic rather than waiting for a morning appointment.