Cats: is this an emergency?

Cats hide illness, which means the gap between 'a bit off' and 'critical' is shorter than it is in a dog. Two things on this page kill cats routinely because they get mistaken for something minor: a blocked bladder that looks like constipation, and open-mouth breathing that looks like a cat being hot.

Go now

Do not wait for morning. Drive, or call ahead and drive.

A male cat straining in the litter box and producing nothing

This is the one people miss. A blocked urethra looks exactly like constipation — the cat crouches and strains, often crying. Merck's own wording is that efforts to urinate are mistaken by owners as constipation. The 2025 international consensus guidelines put waste building up in the blood within 24 to 48 hours of a complete blockage, ending in a ruptured bladder and death. If he is also cold to the touch with a slow heart, potassium is already near the level that stops the heart.

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Open-mouth or laboured breathing

Cats do not pant to cool down and do not pant from stress the way dogs do. Open-mouth breathing in a cat is almost never normal. The Royal Veterinary College's position is that every animal in respiratory distress is an emergency.

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Sudden weakness or paralysis in the back legs, legs cold, crying

A clot has lodged where the aorta splits to supply the hind limbs. It is extremely painful and it comes on in minutes from a cat that seemed fine. Be prepared for a hard conversation — PDSA records roughly 1 in 3 surviving initial treatment, and half of those clotting again within six months. Go anyway, and go now, because pain relief alone is a reason to.

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Any contact at all with a lily

A bitten leaf, pollen licked off her own fur, or water from the vase. Signs start with vomiting and lethargy, increased urination at 12 to 24 hours as the kidneys fail, death within 36 to 72 hours untreated. Treatment begun after about 18 hours generally cannot prevent permanent kidney failure. Peace lilies and calla lilies are different plants and do not do this.

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String or thread hanging from the mouth or the back end

Do not pull it. One end anchors, usually under the tongue, and the gut bunches along the rest of it like fabric on a drawstring — then the string saws through the intestinal wall. If there is slack, cut it. Then drive.

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Pale or white gums

Same test as a dog. Color back in 1 to 2 seconds is normal. White means blood loss or anemia.

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Not eaten for two to three days, especially an overweight cat

Cats mobilise fat faster than the liver can process it, and it clogs the liver. Cornell notes appetite loss of as little as 24 hours can meaningfully affect an adult cat, and kittens under 6 weeks can be at lethal risk after 12 hours. Once fatty liver starts it feeds itself: the cat feels worse, so eats less.

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A seizure over 5 minutes, or more than one in 24 hours

Same threshold as dogs.

Be seen today

Call your vet for an appointment today, not next week.

Not eaten for 24 hours

Call. This is the point at which it stops being fussiness.

Retching repeatedly without producing a hairball

A hairball roughly once a week is normal. Repeated unproductive retching is not.

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Hiding, or a sudden change in how she behaves

In a species that masks illness, behavior change often arrives before any physical sign.

Limping, or a wound or lump that is hot

Cat bites seal over and abscess underneath.

Drinking or urinating noticeably more

Common early sign of kidney disease, diabetes and thyroid disease. Not an emergency, but do not leave it.

Watch and write it down

Not an emergency. Note when it started and how often, and raise it at the next appointment.

One hairball a week or so

Normal grooming behavior.

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Yowling and restlessness in an unspayed female

In heat. Normal, loud, and a good argument for spaying.

A single seizure under 5 minutes with full recovery

Routine appointment.

What normal looks like

Heart rate is the one to be careful with. Merck gives 120–140 bpm, UC Davis gives 200–250, and those do not overlap. A calm cat at home reads far lower than the same cat at the vet. It is also not something most owners can count reliably, so do not use it to make a decision.

On the way

• Call aheadSo they can be ready when you arrive rather than starting from scratch. Say the species, the age, what you have seen and when it started.
• Take the packagingIf a substance is involved. Treatment for rat poison depends entirely on which of the five types it is, and you cannot tell from the color of the bait.
• Write down the timeWhen it started, how long a seizure lasted, when they last ate, when they last passed anything. You will not remember accurately once you are there.
• Keep the carrier dark and quietEspecially for birds, rabbits and cats. Stress alone makes a breathing problem worse, and in a bird in real distress the handling itself can kill.

What not to do

• Do not make them vomitNot unless a vet or a poison line has told you to. Salt can poison them, oil can go into the lungs, and for caustic substances it does more damage coming back up than it did going down.
• Do not give human painkillersOne regular acetaminophen tablet can kill an average cat. Ibuprofen ulcerates the stomach and damages the kidneys in both dogs and cats.
• Do not pull anythingNot string from a cat, not a stuck feather, not prolapsed tissue. Cut string if there is slack, keep tissue moist, and let a vet do the rest.
• Do not put your hands near the mouth during a seizureThey cannot control biting. Time it instead, and move furniture out of the way.
• Do not wait to see if it improves overnightThat sentence is on this page because it is the most common thing owners say afterwards.

Last reviewed October 2026. Written and maintained by Petdeals.io. General care information, not veterinary advice — for a sick animal, call a vet.