Can I give Paracetamol to my cat? (Spoiler: NO — it can kill)

The short answer: **NEVER. Paracetamol is one of the most lethal common poisons for cats.**

Paracetamol (acetaminophen) is the leading cause of cat poisoning deaths worldwide. Cats lack the liver enzyme glucuronyltransferase that safely processes paracetamol in humans and dogs. A single regular-strength adult tablet (500 mg) can kill a 4 kg cat within 24–48 hours if not treated urgently. There is no "safe" or "low" dose of paracetamol for cats — all exposures are a veterinary emergency.

Why paracetamol is deadly specifically for cats

Cats metabolize paracetamol through a minor sulfation pathway (easily saturated) and through CYP2E1, which produces the toxic intermediate NAPQI. In humans and dogs, NAPQI is detoxified by glutathione. Cats have:

1. Extremely limited glucuronidation — the main safe pathway is essentially missing 2. Low baseline glutathione — depletes rapidly 3. Hemoglobin particularly susceptible to oxidation — leads to methemoglobinemia (blood cannot carry oxygen) and Heinz body anemia

Within hours of ingestion: brown-grey gums, facial and paw swelling, vomiting, difficulty breathing, lethargy. Death can follow within 18–36 hours.

Toxic doses in cats

• Any dose above 10 mg/kg is potentially toxic
• 50–60 mg/kg: severe toxicity, frequently fatal
• A single 500 mg tablet = 125 mg/kg in a 4 kg cat = lethal
• Even half a tablet in a kitten is dangerous

Signs to watch for

• Dark (chocolate-brown) gums or blue-tinged gums/tongue (methemoglobinemia)
• Swelling of face, paws, or throat
• Lethargy, weakness, difficulty breathing
• Vomiting, drooling, abdominal pain
• Dark urine (hemoglobinuria)