Is Aspirin toxic to cats?
No. Aspirin is highly toxic to cats — they metabolise it 5–10 times more slowly than humans. Even small doses can cause serious illness.
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Key facts
- Verdict: No — dangerous to cats. Aspirin should never be given deliberately.
- Category: Human painkiller
- Onset: Signs can start 0–4 hours — see the full timeline below.
- If it's already happened: Call your vet now, or the Animal PoisonLine on 01202 509000 (24/7, charges apply) — see the emergency steps below.
If your cat has just eaten aspirin
- Note the dose and number of tablets.
- Call your vet immediately.
- If you can't reach a vet, call Animal PoisonLine (01202 509000) — paid triage, 24/7.
What's the full picture?
Aspirin is toxic to cats because they metabolise salicylates (the active compound in aspirin) extremely slowly — 5 to 10 times more slowly than humans or dogs. This means aspirin accumulates to dangerous levels far faster than expected. Even a single standard human tablet (300–500 mg) is potentially lethal to an average-sized cat. Low-dose aspirin (75 mg) can cause serious harm if ingested repeatedly.
Cats lack the hepatic (liver) enzyme glucuronyl transferase at adequate levels, which is the main pathway for metabolising salicylates. Without it, aspirin and its metabolites build up in the bloodstream, damaging the stomach lining, impairing blood clotting, and — at higher doses — causing respiratory failure and metabolic acidosis.
Symptoms of aspirin poisoning in cats develop over 4–8 hours. Early signs are GI-related: vomiting (sometimes with blood), loss of appetite, and drooling. As toxicity progresses, cats become lethargic and uncoordinated. Severe cases produce rapid breathing, weakness, pale gums, and collapse. Without treatment, aspirin poisoning can be fatal within 24–48 hours.
Aspirin is still found in many UK households — not just as a painkiller, but in some cold and flu remedies, face masks, and anti-dandruff products. If you use aspirin yourself, store it in a secured cupboard. Never give aspirin to a cat as a painkiller — even a quarter of a tablet is unsafe. If your cat is in pain, contact your vet for appropriate cat-safe analgesia.
There is no home treatment for aspirin poisoning. If your cat has ingested any amount of aspirin, contact your vet or the Animal PoisonLine on 01202 509000 immediately. Treatment involves induced vomiting (if recent ingestion), activated charcoal, intravenous fluids, and monitoring of kidney function and blood clotting.
Symptoms to watch for
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Cat owner essentials
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Questions owners ask
Can I give my cat aspirin for pain?
Never. Aspirin is toxic to cats. Even small doses can cause serious harm. If your cat is in pain, contact your vet — there are safe, licensed analgesics for cats including buprenorphine and meloxicam at appropriate feline doses.
How much aspirin is dangerous to a cat?
Any amount should be treated as potentially dangerous. A standard 300 mg aspirin tablet is enough to cause serious toxicity in a cat of average weight. Even low-dose 75 mg aspirin can cause harm if ingested regularly or in combination with other medications.
My cat chewed on an aspirin tablet. What should I do?
Contact your vet or the Animal PoisonLine (01202 509000) immediately, even if your cat seems fine. Aspirin toxicity symptoms can be delayed by several hours, and early veterinary intervention greatly improves outcomes.
Are aspirin and ibuprofen equally dangerous to cats?
Both are very dangerous to cats, but for different reasons. Aspirin causes salicylate toxicity due to slow metabolism. Ibuprofen causes gastrointestinal ulceration and kidney damage. Neither is safe under any circumstances — if your cat has ingested either, treat it as an emergency.
Is baby aspirin safer for cats?
No. Lower-dose aspirin (75–100 mg) is still toxic to cats — it is not a matter of the dose being safe, but rather that cats cannot metabolise salicylates adequately at any dose. Any aspirin ingestion should be treated as a veterinary emergency.
A lockable medicine box is the simplest way to keep human tablets out of reach of a curious cat.
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Related
Sources referenced for this guidance
- Veterinary Poisons Information Service (VPIS) — UK clinical toxicology reference used by vets
- International Cat Care — feline-specific clinical guidance
- BSAVA — British Small Animal Veterinary Association reference materials
- Merck Veterinary Manual — professional veterinary reference
About this guidance
Every entry on this site is compiled from published UK veterinary toxicology sources — International Cat Care, Veterinary Poisons Information Service (VPIS) references, RCVS-registered practice materials, and peer-reviewed feline medicine literature. Where the evidence is mixed, we err on the cautious side because cats are unusually sensitive to many common substances that are harmless to humans and even to dogs.
This is general information written for UK cat owners. It is not personalised veterinary advice for your specific cat, their age, weight, medical history, or the exact exposure you're dealing with. If your cat has eaten something or is unwell, call your vet first. The Animal PoisonLine on 01202 509000 is available 24/7 for a small fee and can tell you whether an emergency visit is needed.
Entries are reviewed and updated as new research emerges. Spotted an error? Let us know — corrections are investigated and applied within 24 hours. For more context on how we work, see about and our full disclaimer.
Last reviewed: · By the What Can My Cat Eat? editorial team