Why is Paracetamol Toxic to Pets?
Pets, especially cats, lack sufficient levels of a specific liver enzyme needed to safely metabolize paracetamol.
This leads to the accumulation of toxic compounds that irreversibly damage red blood cells, preventing them from carrying oxygen (methemoglobinemia), and cause severe, potentially fatal liver damage.
Even a single small tablet can be lethal for a cat, and doses considered safe for humans can poison dogs.
Why speed matters
Delaying care significantly worsens outcomes. Some signs appear hours or days later, so "looks fine right now" is not a reason to wait.
Signs to watch for
- Difficulty breathing, rapid breathing, or blue/grey gums (signs of oxygen deprivation)
- Swelling of the face, paws, or neck
- Lethargy, weakness, and collapse
- Vomiting, drooling, and loss of appetite
- Brown or chocolate-colored gums (methemoglobinemia)
- Jaundice (yellowing of the skin, gums, or eyes) indicating liver damage
What to do right now
- Call your veterinarian or a pet poison control center immediately. This is a time-critical emergency.
- Do NOT induce vomiting unless specifically instructed by a veterinary professional.
- If possible, provide the product name, strength (mg), and estimated amount ingested.
- Do not give any other medications or home remedies.
- Be prepared to transport your pet to the veterinary clinic for urgent treatment, which may include inducing vomiting (if safe), administering an antidote (acetylcysteine), and supportive care.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.
The step-by-step response, from the first minute to the vet visit, is in our Paracetamol Poisoning in Dogs and Cats emergency guide.