Why Is My Cat Shaking After Surgery?

Shaking or trembling in the first 12–24 hours after surgery is usually one of three things: a drop in body temperature from anesthesia, the drugs themselves wearing off, or pain that the medication has not fully covered. It typically resolves within a day. Shaking that continues past 24 hours, gets worse, or comes with pale gums, a swollen belly, or a cat that cannot be roused is a same-day call to the vet.

A trembling cat is frightening to watch, and the instinct is to assume something has gone wrong with the surgery. Most of the time, nothing has. The body is cold, confused, or sore — and each of those has a fix you can start on at home.

Why do cats shake after anesthesia?

Three causes account for nearly all post-operative trembling.

Low body temperature. Anesthesia switches off the body's ability to regulate heat. A cat's normal temperature runs 100.5–102.5°F, and it is common for a cat to come home a degree or two below that after a procedure. Shivering is the body trying to generate heat. Clinics warm cats during recovery, but a small cat on a cold car seat in winter can lose ground on the way home.

The drugs wearing off. Several anesthetic and sedative agents cause muscle tremors as they clear the system. Ketamine — used in most feline spay and neuter protocols — is a well-known cause of twitching and trembling for several hours. Opioids like buprenorphine can do the same. This kind of shaking looks like fine muscle twitches or a whole-body tremble that comes and goes, and it fades as the drugs are metabolized over 12–24 hours.

Pain. A cat in pain will often tremble, crouch, and hold very still. Cats hide pain far better than dogs, so trembling may be the only sign you see. If the shaking started or got worse as the clinic's pain injection wore off — usually 8–12 hours after surgery — and the cat has not yet had the take-home dose, pain is the likely driver.

A fourth, less common cause is stress. A cat that has spent the day in a clinic, in a carrier, and in a car may shake from adrenaline alone once it gets home. This looks like trembling plus wide pupils, flattened ears, and hiding. Our guide on why cats hide after surgery covers the settling-in period.

How can I tell if my cat is cold, in pain, or just groggy?

Check three things, in this order.

Ears and paws. Touch the ear tips and paw pads. If they feel cold and the cat is shivering, temperature is the problem. Warm the cat first — see below — and reassess in 30 minutes.

Posture. A groggy cat lies loosely, often on its side, and trembles intermittently. A cat in pain crouches tightly, tucks its legs under, keeps its eyes half-closed, and may growl or flinch if you approach the incision. If the crouch is the dominant picture, pain medication is overdue or insufficient.

Response to you. A cold or groggy cat will look at you, blink, and may try to move toward you. A cat in significant pain avoids contact. A cat that does not respond at all — no ear flick, no eye movement — needs the emergency line, not a warm blanket.

Wobbly walking alongside the shaking is expected on day one. Our article on why cats are wobbly after surgery separates normal ataxia from the warning signs.

How do I warm up a cold cat after surgery?

Gently, and without direct heat on the skin.

Set the cat up in a small, warm room — a bathroom or a bedroom with the door closed, 72–75°F if you can manage it. Line a low-sided box or a cat bed with a fleece blanket. Add a heating pad on the lowest setting under half of the bed, wrapped in a towel, so the cat can move off it. A heating pad on high, or a hot water bottle directly against a sedated cat, can cause burns — a cat that cannot move well cannot move away from heat.

Do not bathe the cat or use a hair dryer. Do not wrap the cat tightly; it needs to be able to shift position.

Most cats stop shivering within 30–60 minutes of being warmed. If the trembling continues past an hour in a warm room, temperature was not the cause.

When is shaking after surgery an emergency?

Call the clinic or the emergency line the same day if any of these are present:

Shaking past 24 hours, or trembling that is getting stronger rather than fading.

Pale, white, or blue-tinged gums. Lift the lip and look. Gums should be pink. Pale gums with trembling can indicate internal bleeding or shock.

A swollen, tight, or painful belly in a cat that has had abdominal surgery.

Rapid breathing at rest — more than 40 breaths a minute while lying still. Count the chest rising for 15 seconds and multiply by four. Our guide on fast breathing after cat surgery covers the thresholds.

A cat that cannot be roused, or one that is trembling continuously and unable to stand after the first 12 hours.

Trembling plus vomiting, drooling, or refusal of water past 24 hours.

An incision that is bleeding, open, or discolored. Compare against our guide to what a healing cat spay incision should look like.

Should I take the recovery collar off while my cat is shaking?

No. A trembling cat is still a cat that will groom the incision the moment it feels well enough — and the moment it feels well enough often arrives faster than the moment you notice.

Check the fit instead. A hard plastic cone on a cold, groggy cat is a real problem — it prevents the cat from curling up, which is how cats conserve heat. An inflatable recovery collar sits at the neck and lets the cat curl into a tight ball on the warm bed, tuck its nose under a paw, and rest. Cats warm up faster in a collar that lets them curl.

Run the two-finger fit check: two fingers should slide flat between the strap and the neck. A collar that is too tight adds stress to a stressed cat. If she is fighting the collar on top of everything else, our guide on keeping a cat calm after surgery covers the room setup that settles most cats.

Frequently asked questions

My cat's head or legs twitch while sleeping. Is that the same thing?

Usually, yes — muscle twitching during sleep in the first day is a drug effect, most often ketamine. It resolves on its own. Full-body seizure activity — rigid limbs, paddling, loss of bladder control, unresponsiveness — is different and is an emergency.

Can I give my cat anything for the shaking?

Only the pain medication the clinic dispensed, at the prescribed time. Never give human pain relievers — acetaminophen and ibuprofen are toxic to cats. If the take-home dose is not due for hours and the cat is clearly in pain, call the clinic and ask whether to move it up.

How long does anesthesia take to wear off in cats?

Most cats are steady on their feet within 12 hours and back to baseline behavior within 24–48 hours. Older cats and cats with kidney disease take longer. Our article on senior cat surgery recovery covers what changes for cats over 10.

My cat is shaking and won't eat. Is that connected?

Often. Cold, pain, and nausea all suppress appetite on day one. Warm the cat, give the pain medication on schedule, and offer a tablespoon of warmed wet food. A cat that has eaten nothing in 24 hours needs a call regardless of the shaking.

Warm, medicate, watch the clock

A warm room, the pain dose on time, and a cat that is trending better each hour — that is what a normal first night looks like. Trembling that is fading by morning was cold, drugs, or both. Trembling that is not is the reason the clinic gave you an after-hours number.

Keep the incision protected through all of it. The BENCMATE cat recovery collar range sits at the neck and lets a cold cat curl up tight — which is exactly what she needs to do tonight.