Go to a vet now
This is an emergency: go to a vet immediately. Acetaminophen (Tylenol, paracetamol) is extremely toxic to cats. Signs have been reported at 10 mg/kg, so even part of one tablet can kill a cat.
What to do right now
- Go to a vet or emergency clinic immediately.
- Call poison control on the way if you can.
- Bring the package.
Why tylenol can be dangerous for cats
Cats lack the liver enzymes needed to safely process acetaminophen. It damages red blood cells, turning hemoglobin into methemoglobin, which cannot carry oxygen. Merck reports toxicosis in cats generally at 40-50 mg/kg, with signs in some cats at 10 mg/kg.
Symptoms to watch for
- Brown, gray or blue gums
- Difficulty breathing, fast breathing
- Swelling of the face and paws
- Drooling and vomiting
- Dark urine
- Weakness and collapse
What not to do
- Never give acetaminophen to a cat.
- Do not wait for signs.
What the vet will do
Treatment includes the antidote N-acetylcysteine, oxygen, decontamination and sometimes blood transfusion. Survival depends on how quickly treatment starts.
Related guides
Cat ate tylenol: FAQ
How much Tylenol is toxic to a cat?
Signs have been reported at 10 mg/kg. For a 10 lb cat, that is about 45 mg, a fraction of one regular 325 mg tablet.
Other "my cat ate…" guides
- String, Thread or YarnEmergency
- PlasticCall your vet
- Rubber Band or Hair TieCall your vet
- IbuprofenEmergency
- Chicken BoneCall your vet
- BugWatch closely
Sources
- Merck Veterinary Manual: Toxicoses From Human Analgesics in Animals
- ASPCA Animal Poison Control Center
This guide is general information, not a diagnosis. Every pet is different: when in doubt, call your vet or an animal poison control line.