A cat with a broken leg does not need the bone set at home. It needs 3 things in the next 10 minutes: a rigid splint that spans the joint above and the joint below, 3 pressure points that hold the limb in the position you found it, and a flat carry that keeps the spine in 1 line. Pulling the leg straight, testing whether it bears weight, or giving a human painkiller each turn a repairable fracture into a limb that ends in amputation.
Fracture or sprain: 4 checks in 2 minutes
Look for 4 things and stop touching. First, the leg does not touch the ground and the cat holds it at an angle it never stands in. Second, there is a 2 to 5 cm step or a grating feel where the bone should be smooth, and a 1 to 2 cm shortening against the other side. Third, swelling that grows visibly in 15 minutes, with a bruise appearing over 6 to 12 hours. Fourth, the cat will not let you run a hand from hip to toe, and complains at 1 specific point rather than the whole limb. A sprain hurts everywhere and bears 30 to 50% of weight within 24 hours; a fracture gives 1 sharp spot, no weight at all, and a limb that swings from the middle. Do not test by pulling or twisting. About 80% of cat fractures come from a fall of 1 to 3 floors, a car at 30 km/h or more, or a door closing on a limb, and 1 in 5 of those cats has a second injury in the chest or pelvis that matters more than the leg.
Three-point splinting, on the limb where it lies
A splint works by 3 points of pressure: 1 pad at the joint above the break, 1 at the joint below, and 1 pad on the opposite side of the limb at the level of the break. together they form a bridge that stops the two bone ends from grinding. A splint that only wraps the break, with no joint above and below, acts as a hinge and does more harm than none. Use a rigid strip 3 to 5 mm thick: a folded magazine, a 30 cm ruler, or 5 mm plywood. Pad with 1 cm of cotton or a sanitary pad, then wrap with self-adhesive bandage at 50% stretch, tight enough to hold and loose enough for 1 finger to slide under.
| Limb | Splint length (cm) | 3 points of contact | Wrap width (cm) | Recheck (min) |
|---|---|---|---|---|
| Front, below elbow | 15 to 20 | elbow, mid-forearm, paw | 5 | 20 |
| Front, whole leg | 25 to 30 | shoulder, elbow, paw | 7.5 | 20 |
| Hind, below stifle | 20 to 25 | stifle, mid-shin, paw | 7.5 | 20 |
| Hind, whole leg | 30 to 35 | hip, stifle, hock | 10 | 15 |
| Pelvis or spine | 60 to 90 board | shoulder, hip, tail base | 10 | 10 |
Check the toes 5 minutes after wrapping and every 20 minutes after that: pads should be pink and warm. Cold pads, a swollen paw, or a cat that chews at the bandage means the wrap is too tight and it comes off, not looser. A bandage left on for 60 minutes at full stretch can cause tissue death under it.
Why straightening the leg costs the limb
A fractured femur or tibia usually has 2 or 3 fragments, and the sharp end of 1 fragment sits against a 1 to 2 mm artery or the sciatic nerve. Pulling the limb into a straight line drags that edge along the vessel. The limb looks straighter and the cat screams less, which convinces owners they helped; 20 minutes later the paw is cold. A fracture that is fixed within 24 to 72 hours has a good chance of full use. One with a torn artery has a 6-hour window before muscle dies, and amputation rates in that group run far higher. Splint in the position found, even if it looks wrong, even if the foot points 30 degrees out.
Lift along the body axis, on a board
Use a rigid board at least 10 cm longer than the cat, nose to tail base, with a towel roll on each side at 5 cm diameter. Slide the board under the cat rather than lifting the cat onto it, and have a second person support the head and the pelvis at the same time. Tape across the board at 3 points: chest, hips, and mid-body, over the towel rolls, never across the neck. Keep the spine and the injured limb in 1 plane; a cat carried with its hind end hanging bends the fracture and can convert a closed fracture into an open one. Do not use a soft carrier alone, because the cat will turn inside it.
Open fracture: wet gauze for 10 minutes
If bone is visible, cover it with gauze soaked in 0.9% saline at room temperature and keep it wet for the 10 minutes it takes to reach the car, re-wetting every 2 to 3 minutes from a squeeze bottle. A dry gauze bonds to the bone surface and strips periosteum when it is lifted. Do not push the bone back in. Do not pour iodine, alcohol or hydrogen peroxide into the wound; all 3 kill the bone surface that has to heal. Add a second dry layer over the wet one, wrap once with 50% stretch, and stop if the toes swell. An open fracture is a 1-hour emergency: infection risk climbs with every hour past 6, and the cat needs antibiotics and surgical cleaning, both on veterinary prescription only.
Pain relief is a prescription, not a cupboard
Cats lack the glucuronyl transferase pathway that clears many human drugs, so the usual household painkillers are poisons. Ibuprofen at 1 adult tablet can cause acute kidney injury in a 4 kg cat. Acetaminophen at 1 tablet causes methemoglobinemia, with brown gums and laboured breathing, often inside 24 hours. Aspirin at 1 tablet causes gut ulceration and bleeding that may not show for 3 to 5 days. Pain control for a fracture is a veterinary decision, usually an opioid given at the clinic and an NSAID licensed for cats after the fracture is assessed, and the dose depends on kidney values.
Do this in the next 10 minutes
- Look, do not pull. Note the angle and leave the limb where it is.
- Pad 3 points: above the break, below the break, and opposite the break.
- Wrap with a rigid strip and 50% stretch bandage, then check the toes at 5 minutes.
- Slide a board under the cat, tape at 3 points, carry flat with 2 people.
- Cover an open wound with saline gauze and keep it wet every 2 to 3 minutes.
- Call ahead, say fracture and the hour it happened, and give no painkiller and no food.
If the cat was also hit by a car, read first aid basics for shock and gum checks, and if the cat is panting or overheated from being trapped in a carrier, use the cooling steps in heatstroke first aid before you move it.
Terms mentioned in this article
Frequently asked
Should I try to straighten the leg before splinting it?
No. A fractured femur or tibia usually has 2 or 3 fragments, and a sharp edge often sits against a 1 to 2 mm artery or the sciatic nerve. Pulling the limb straight drags that edge along the vessel, and the paw can go cold within 20 minutes. Splint in the position you found, with 3 pressure points: above the break, below the break, and opposite the break. Fixation inside 24 to 72 hours gives the best chance of full use.
Can I give my cat half an ibuprofen or a child's pain syrup?
No. Cats lack the glucuronyl transferase pathway that clears many human drugs. One adult ibuprofen tablet can cause acute kidney injury in a 4 kg cat, 1 acetaminophen tablet causes methemoglobinemia with brown gums, and 1 aspirin causes gut ulceration that may not show for 3 to 5 days. Do not split a dog's carprofen either. Pain relief for a fracture is given on veterinary prescription, after the limb and the kidneys are assessed.
The bone is sticking out. Do I push it back in and wash the wound?
Do not push it back. Cover the bone with gauze soaked in 0.9% saline and keep it wet for the 10 minutes it takes to reach the car, re-wetting every 2 to 3 minutes. A dry gauze bonds to bone and strips periosteum when lifted. Skip iodine, alcohol and hydrogen peroxide, which kill the bone surface. An open fracture is a 1-hour emergency, and antibiotics plus surgical cleaning come on prescription only.
Related guides
- Cat Choking: 5 Seconds to Look, 5 Back Blows, 2 Minutes Max
- Cat Heatstroke: Cool to 39.5 C, Then Stop
- Cat Hypothermia: Rewarm at 0.5 C per Hour, Not 2
- Cat Poisoning First Aid: 60-Minute Window, 6 Lethal Doses
- Heat Exhaustion in Cats: 0.5 C Every 10 Minutes
- Cat Burn First Aid: 20 C Water, 10 to 20 Minutes