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)
• Collapse

Call an emergency veterinarian at the first sign, even if you are not 100% sure of ingestion.

Emergency treatment (given by vet)

• N-acetylcysteine (NAC) IV — the antidote, must be given within hours
• Methylene blue for methemoglobinemia
• Activated charcoal if very recent ingestion
• Oxygen therapy
• Aggressive IV fluids
• Vitamin C, SAMe — adjunct antioxidants
• 48–72 hours of intensive care monitoring for hepatic necrosis and hemolysis

Prognosis depends on time-to-treatment: treated within 4 hours, survival is good; treated after 12 hours, mortality is high.

What to use for cat pain (only under veterinary direction)

Veterinary options include meloxicam, robenacoxib (Onsior), buprenorphine, or gabapentin — at cat-specific doses prescribed by a vet. Never share human pain medication with cats.

Clinical sources

• Plumb's Veterinary Drug Handbook — feline acetaminophen toxicity.
• ASPCA Animal Poison Control Center — top 10 toxic substances for cats.
• MacNaughton SM. "Acetaminophen toxicosis in a Dalmatian." Can Vet J.
• Court MH, Greenblatt DJ. "Molecular basis for deficient acetaminophen glucuronidation in cats." Biochem Pharmacol (PMID: 9063383).
• Merck Veterinary Manual — "Acetaminophen Toxicosis."

Bottom line

Paracetamol is one of the most dangerous household substances for cats. Never, under any circumstances, give it to a cat. If accidental exposure occurs, it is a veterinary emergency — call the emergency clinic or Pet Poison Helpline (US: 855-764-7661; UK: 01202 509000) immediately.

Store all paracetamol and other human pain medication well out of reach of cats. If ingestion is suspected, seconds count — act immediately.