My cat got into ibuprofen.
Call now.
Cats sit at the unlucky end of NSAID sensitivity: published guidance treats them as roughly twice as sensitive as dogs, and there is no safe feline dose of ibuprofen. One standard 200 mg tablet overshoots the toxic line for every cat that exists.
A 200 mg tablet in a 4-5 kg cat is 40-50 mg/kg, far beyond the level where stomach ulceration and kidney injury are expected in the species that clears NSAIDs worst. Whether your cat chewed a dropped pill, licked liquid-capsule contents, or was given "half a tablet to help her limp", the answer is the same: call poison control now and expect a vet visit. Early decontamination, GI protectants, and fluids work; waiting for vomiting or lethargy hands the drug a day's head start.
Pet Poison Helpline · 855-764-7661 ASPCA Poison Control · 888-426-4435What ibuprofen does to cats
Stomach and intestinal ulceration (vomiting, sometimes with blood; dark tarry stools; appetite loss) and kidney injury (drinking and urinating changes, then lethargy) over 1-4 days. Cats hide pain and nausea well, so visible signs arrive late in the process.
The routes that actually happen
Dropped pills batted and chewed, liquid-gel capsules punctured during play, pills in bags and purses, and well-meaning dosing by owners. No human NSAID (ibuprofen, naproxen, aspirin) or acetaminophen is safe to give a cat; feline pain control exists only through a vet. A dog in the house too? Dogs get their own math: ibuprofen calculator for dogs.
What NOT to do
Do not wait for symptoms. Do not induce vomiting in cats at home. Do not give any follow-up human medication, including Pepto-style products (salicylates, also toxic to cats).