Guide to Paracetamol Poisoning - A Vet Emergency
Paracetamol is a common human painkiller that can be highly toxic to dogs and cats. Even small amounts can cause severe illness, and poisoning can be fatal, particularly in cats.
Most cases occur when a pet accidentally eats tablets left within reach or is given paracetamol by an owner unaware of the risks. If you think your pet has swallowed paracetamol, seek veterinary attention immediately.
Written by Gillian Burkhill, Veterinary Surgeon, Animal Trust Vets CIC | Published July 2026 | Review date July 2029 | This advice is for UK pets only and is not a replacement for seeing a vet
Symptoms of paracetamol poisoning in cats & dogs
Symptoms usually develop within a few hours of ingestion.
Common signs include:
Swollen face or paws
Brown or blue-tinged gums
In severe cases, pets may collapse, develop liver failure or die if left untreated.
When is it an emergency?
Paracetamol poisoning is always an emergency. Contact your veterinary practice immediately if you know or suspect your dog or cat has swallowed paracetamol, even if they seem well.
Do not wait for symptoms to develop. Early treatment gives your pet the best chance of recovery.
If possible, take the medication packaging with you so your vet can identify the strength and estimate the amount your pet may have ingested.
Diagnosis
Your vet will diagnose paracetamol poisoning based on your pet's history, clinical signs and a physical examination. Blood tests may be recommended to assess liver function and the severity of poisoning.
Treatment of paracetamol poisoning in cats & dogs
Treatment depends on how much paracetamol has been ingested and how quickly your pet is seen by a vet.
If treatment is started soon after ingestion, your vet may induce vomiting to remove the tablets before they are absorbed. Additional treatment may include activated charcoal, intravenous fluids and medications to support the liver.
Paracetamol poisoning can also be treated with an antidote called N-acetylcysteine (NAC). This is most effective when given as soon as possible after ingestion, although it may still be beneficial in pets treated later.
Some pets require hospitalisation and close monitoring. Early treatment significantly improves the chances of a successful recovery.
Prevention
Store all medications securely out of reach of pets and never leave tablets where they can be easily accessed. Never give paracetamol to a cat. Paracetamol should only ever be given to a dog if it has been prescribed by your veterinary surgeon. If you think your pet is in pain, contact your veterinary practice, as there are safe and effective pain relief medications available for dogs and cats.
Outlook
The outlook depends on how much paracetamol has been ingested, how quickly treatment is started and whether liver damage has developed. Pets treated promptly often make a good recovery. However, delayed treatment or severe poisoning can result in permanent liver damage and, in some cases, may be fatal.