Cat hit by a car: the first hour, and the injuries that appear later

Quick answer

Every cat that has been hit by a car needs a vet the same day, including the ones that walk away from it.

A cat struck by a vehicle has taken a blunt force injury to the whole body. The visible damage is rarely the dangerous part.

The three things that kill cats after a road accident are bleeding into the chest or abdomen, a lung injury that worsens over the following day, and a ruptured bladder that stays silent for two or three days. None of them are obvious at the roadside, and all of them are treatable if the cat reaches a vet early.

• Get the cat off the road safely, contain it in a box or carrier, and go straight to a vet. Do not wait to see how it looks in the morning.
• Assume it will bite. Pain turns the gentlest cat into a biting animal, and a cat bite to a human hand is itself a medical emergency.
• Open-mouth breathing in a cat is always an emergency. Cats breathe through the nose; a cat breathing through its mouth is in trouble.
• Give nothing by mouth: no food, no water, no painkillers. Paracetamol and ibuprofen kill cats, and a full stomach delays the anaesthetic.
• Phone the clinic while someone else drives, so they can have oxygen and a triage team ready when you arrive.

:::danger
Never give a cat any human painkiller after an accident.

Cats lack enough of the liver enzyme that clears paracetamol (acetaminophen), so the drug is diverted into a metabolite that destroys haemoglobin and liver cells. The cat's blood turns brown, the face and paws swell, and the cat suffocates on blood that can no longer carry oxygen. Ibuprofen and aspirin cause stomach ulceration and kidney failure at doses a person would consider trivial. There is no safe household painkiller for a cat.
:::

Decide in 60 seconds

Why the injuries you cannot see are the ones that matter

A car transfers energy into the whole animal at once. The skin and the skeleton absorb some of it, and the rest passes through to the organs.

Three patterns account for most of the deaths that happen after the cat has already been recovered alive.

Pulmonary contusion.

Blunt impact bruises the lung tissue itself. Blood and fluid leak into the air spaces over the hours that follow, so the amount of working lung falls steadily while the cat looks progressively worse rather than better. This is the single commonest reason a cat that seemed fine on the night is in distress the next morning. It is managed with oxygen, rest, careful fluid therapy and time, and it needs to be recognised before the cat crashes.

Pneumothorax and diaphragmatic rupture.

Air can escape from a torn lung into the chest cavity and press the lungs closed, or the impact can tear the diaphragm and allow the liver, stomach and intestines to slide into the chest. Both produce fast, shallow, effortful breathing and a cat that will not lie on its side. A diaphragmatic tear can also be quiet at first and only declare itself days or weeks later when the cat is offered a large meal.

Uroabdomen from a ruptured bladder.

This is the injury owners are least prepared for. The cat is stable for a day or two, then becomes flat, stops eating, and vomits. Urine leaking into the abdomen is reabsorbed, so potassium and waste products climb in the blood and the heart slows dangerously. The tell is a cat that either passes no urine at all, passes small amounts of bloody urine, or has an abdomen that feels fuller and more uncomfortable each day.

Alongside these sit pelvic fractures, sacrocaudal (tail-pull) injuries where the nerves to the bladder and hind legs are stretched, head trauma, and degloving wounds where skin is stripped off a limb and the underlying tissue dies slowly over the following week.

The first minutes at the scene

Protect yourself before you touch the cat.

Stop traffic or get someone to. A second casualty helps nobody. If you are alone on a fast road, put hazard lights on and approach from the direction traffic can see you.

Assume the cat will bite and scratch.

Pain-induced aggression is a reflex, not a temperament. Cover the cat with a coat, jumper or towel before your hands go near it, and keep your face well away. Cat bites inject bacteria deep into human tissue through a puncture that seals over, and they infect readily; a bite to the hand or wrist needs same-day human medical attention wherever you live.

Move the cat as one piece.

If the cat is unable to stand, slide it onto something rigid rather than lifting it: a car boot liner, a piece of cardboard, a chopping board, a folded coat pulled taut. Support the spine and pelvis together. Do not lift a cat with a suspected pelvic or spinal injury under the belly, because that hinges the fracture.

A carrier that opens from the top, a rigid base, towels and non-stick dressing pads are the whole of a useful cat trauma kit. Nothing here needs to be expensive.

Contain, do not carry.

A cat carried loose in a car will struggle, hide under a seat, or escape at the clinic door. Use a carrier that opens from the top if you have one, or any sturdy box with air holes and a towel in the base.

Keep the cat warm, not hot.

Shock drops body temperature, and a cold cat responds badly to anaesthesia and clots poorly. Wrap in a dry towel or blanket. Do not use a hot water bottle directly against the skin and do not put a heat source on a cat you cannot assess, because warming a shocked cat too aggressively pulls blood away from the organs into the skin.

Reading the cat without handling it

You can learn most of what a triage nurse learns in the first minute, from a metre away.

Breathing.

Count the rise and fall of the chest for fifteen seconds and multiply by four. A resting cat at home usually breathes comfortably below about thirty breaths a minute, and clinics use a resting rate above that as their alarm threshold. What matters more than the number is the effort: nostril flare, elbows held away from the body, the belly working hard, or the head and neck stretched forward all mean the cat is fighting for air.

Mouth breathing.

A cat breathing through an open mouth without having just run or been extremely stressed is an emergency in every context, not only after trauma. Do not delay to examine anything else.

Lifting the lip takes two seconds and tells you about circulation. Only do it if the cat is breathing comfortably enough to tolerate it.

Gum colour and capillary refill.

Healthy feline gums are bubblegum pink and moist. Press a fingertip on the gum for a second and lift: the blanched spot should refill in under two seconds.

Pale or white gums with slow refill mean blood loss or shock. Blue or grey means oxygen is not reaching the tissues. Brick red can mean early shock or sepsis. Yellow means red cells are being destroyed or the liver is failing, which is not an immediate trauma sign but matters if it appears days later.

Skip this check entirely in a cat that is struggling to breathe. Restraining a cat with a chest injury to look at its gums can kill it.

Posture and pain.

Cats show pain in the face before they show it in behaviour. Ears rotated outwards and flattened, a tense muzzle, eyes narrowed with the skin around them tightened, whiskers pulled forward or stiffly straight, and the head held low are the recognised feline pain expressions. A cat sitting hunched with all four feet under it and refusing to settle is in pain, even if it is purring. Cats purr when distressed as well as when content.

Urine and abdomen.

Note whether the cat has passed urine since the accident, what colour it was, and whether the belly looks or feels more distended each time you check. Take that history with you.

The cat that ran off

Most cats hit by a car are not found at the roadside. They bolt, and a frightened cat's instinct is to go to ground in the nearest dark, tight space rather than to run far.

Search low and close: under parked cars, in hedge bases, under decking and sheds, in garages and outbuildings within a few properties in every direction. Take a torch even in daylight, because eyeshine gives cats away in dark cavities.

Search again at dusk and again before dawn, when the street is quiet and an injured cat is more likely to answer. Shake a food container rather than calling in a loud voice.

Tell the neighbours to check their sheds and to leave garage doors open a crack. Ring the local veterinary clinics and any out-of-hours service, because a good samaritan may have taken the cat in already, and ask them to record your number against the description.

Ask about the local authority or highways service too. In many countries, dead or injured animals collected from the road are scanned for a microchip, but the practice varies and in some places it does not happen at all. Wherever you live, keeping the microchip registration up to date is the single change that most improves the chance of being contacted.

What the vet will do, and what to bring

Knowing the sequence makes the appointment faster and stops you feeling that nothing is happening.

Triage comes first: oxygen, pain relief, and warmth before any diagnostics. Strong pain relief in cats is usually an opioid such as buprenorphine or methadone, given by injection, and it is given early because pain worsens shock.

Circulation is assessed and supported with intravenous fluids, guided by heart rate, pulse quality, gum colour, blood pressure and blood lactate. A packed cell volume and total solids sample takes minutes and shows whether the cat is bleeding.

Ultrasound comes before x-rays. Quick focused scans of the chest and abdomen look for free fluid and free air without moving the cat much. Radiographs of the chest, pelvis and spine usually wait until the cat is stable enough to be positioned, because taking films of an unstable cat is a common way to lose one.

Urine output is measured. If a ruptured bladder is suspected, the vet can compare the creatinine and potassium concentration in abdominal fluid against the blood, which confirms uroabdomen quickly.

Surgery is often delayed deliberately. Fractures and hernias are usually repaired after two or three days of stabilisation, not on the night, because anaesthetising a cat with bruised lungs is far more dangerous than waiting.

Bring with you: the time of the accident, whether the cat was seen to be hit or found afterwards, whether it lost consciousness, whether it has urinated and what the urine looked like, its usual weight, any medication it takes, and photographs of anything that has changed. If the accident was unwitnessed, say so; a cat found injured at the roadside might equally have fallen, been attacked, or been caught in a trap, and that changes what the vet looks for.

Days one to seven: what to watch at home

Discharge is not the end of the risk period.

Hours 12 to 48.

Breathing rate and effort, counted at rest and written down three or four times a day. A rising resting rate is the earliest sign that lung bruising or fluid is progressing.

Days one to three.

Urination. Every pass, its volume, and its colour. No urine, straining without production, or a belly that grows firmer is a bladder emergency.

Days three to ten.

The skin over any area that took a heavy impact. Degloving injuries and crushed tissue can look intact for several days and then turn dark, cold and leathery as the blood supply fails. Wounds that were closed can break down as the deeper tissue declares itself.

Throughout.

Appetite, and the ability to get comfortable. A cat that has not eaten for two days needs veterinary attention regardless of the reason, because cats mobilise fat into a liver that cannot process it and develop hepatic lipidosis.

The routine that reduces the risk

What never to do

Do not give food or water. A cat that may need an anaesthetic in the next few hours is safer with an empty stomach, and a cat with head or chest injury can inhale what it swallows.

Do not give any human medicine, including paracetamol, ibuprofen, aspirin and any combined cold remedy.

Do not splint a limb. Home splints applied to a fractured cat's leg cause pressure sores and can turn a simple fracture into an open one. Support the whole cat instead.

Do not clean wounds with hydrogen peroxide, surgical spirit, alcohol or undiluted disinfectant. They kill the tissue that has to heal. Cover with a clean, non-stick dressing or a clean cloth and leave it for the vet.

Do not pull out anything impaling the cat. It may be the only thing preventing catastrophic bleeding.

Do not put the cat in a cage or box with a wire floor, and do not transport it loose on a lap.

Do not wait until morning because the cat is purring and grooming. Both are compatible with severe injury.

Recovery from a road accident is measured in weeks of restricted, quiet indoor space, not in a single good evening.

When to get help

Travel immediately, phoning ahead, for any of these:

• Open-mouth breathing, or fast breathing with visible effort
• Pale, white, grey or blue gums
• Collapse, unresponsiveness, or a seizure
• Bleeding that does not slow with pressure
• Inability to stand, or dragging the hind legs
• A limp tail with urine or faeces leaking
• An abdomen that is swelling, or no urine passed since the accident
• Anything protruding from a wound

Book a same-day appointment, even in a cat that seems well, for any known or suspected collision. Ask specifically for the chest to be assessed and for the bladder to be checked, and say when the accident happened.

Go back within twenty-four hours if the resting breathing rate rises, the cat stops eating, the abdomen grows, urine stops, or a bruised area turns cold, dark or hard.