Paracetamol poisoning in cats

Don’t give the cat your pills: paracetamol poisoning
in cats

Introduction

This month in our Keeping Cats Safe campaign we are looking at paracetamol poisoning. This simple over the counter medication is used frequently by people managing pain, but did you know that the drug is highly toxic to cats, with just one tablet causing death in some cases? It is worth remembering to never give cats or dogs human medication as they can react very differently to you and I. Paracetamol comes in many different forms for people and all can harm our pets, this includes liquid formulations designed for children, tablets and powders.

How are cats poisoned with paracetamol?

Sadly, the majority of cases are due to well-meaning owners giving part or a whole tablet, or a few millilitres of a paracetamol containing suspension to their cat. Occasionally a curious cat will chew a tablet that hasn’t been stored out of reach. It is important to keep any human medications out of reach of both pets and children.

Why is paracetamol toxic to cats?

Cats are very sensitive to paracetamol, more so than dogs and humans. In all species paracetamol is broken down by the liver, but cats do this in a different way and unfortunately this produces a toxic chemical which results in several severe complications. These include severe liver damage, and a reduction in the ability of red blood cells to carry oxygen around the body.

What are the signs of paracetamol toxicity in cats?

Affected cats will become very unwell, their gums may take on a bluish colour and they will have a fast heart rate and difficulty breathing. They will likely be very depressed and may develop swelling of the paws and face. Without treatment they may start to vomit and pass dark brown urine, and their skin may start to look yellow in colour (jaundice). Unfortunately, cats will die if they are not taken to the vet and treated quickly.

Can affected cats be treated?

Yes, but they need to be taken to the vet immediately and the vet informed as to what medication has been given and how much. The vet should then contact a poisons advice service such as the Veterinary Poisons Information Service (VPIS) who will provide specific treatment advice. If the cat was given or ate the paracetamol a short time before going to the vet, they may be made to be sick or treated with activated charcoal to try and stop the paracetamol being absorbed.

The aim of ongoing treatment is to try and prevent the cat’s own body breaking down the paracetamol into more toxic chemicals using an antidote. The antidote for cats is a drug called acetylcysteine and it may be available from a local human emergency department. In addition, affected cats are treated with oxygen, fluids and even blood transfusions.

What is the prognosis for affected cats?

The prognosis really depends on how quickly a cat is taken to the vets and if they can be given the antidote. Fast actions by an owner realising their cat has eaten paracetamol or promptly telling the vet they have given the drug can save a cat’s life. If treated rapidly the prognosis is good, but treatment can be intensive and expensive. If a cat is not seen for several hours after consuming paracetamol they may not survive.

What alternatives are used to manage pain in cats?

There are many painkilling drugs (analgesics) available for cats. They MUST be prescribed by a veterinary surgeon. If anyone is worried their cat is unwell or in pain, they should speak to their vet and never give drugs prescribed for themselves or another pet to their cat.

 

Cases

A 15 year old Domestic Short-haired cat was given two 500mg paracetamol tablets by his owner as she was concerned he was unwell and in pain perhaps due to arthritis. One tablet was given the night before and the next on the morning of presentation to the veterinary surgeon. On examination he had developed pale and bluish gums, increased breathing rate and severe swelling of the face and paws. He was treated with various drugs and he improved slightly over a 3 day period but then deteriorated and was put to sleep 7 days after being given the tablets as he was struggling to breathe. The owner meant well and acted out of concern for her cat but of course consulting a vet for cat-safe pain killers is always the best course of action.

An 8 year old Domestic Long-haired cat was given a quarter of a paracetamol tablet by the owner because he had been unwell and seemed tired. Four hours later the owner was alarmed to see the cat was panting and distressed. The local vet saw pale gums and cold paws. Blood tests showed he was anaemic. He was given activated charcoal to try and stop the absorption of the drug and started on the paracetamol antidote (acetylcysteine) but died 12 hours after admission.

A 6 month old Domestic Short-haired cat ingested one 500 mg paracetamol tablet by chewing the packet which had been left out. By 3 hours she had lethargy, chocolate brown blood (due to a paracetamol-induced changes to haemoglobin, the oxygen carrying component of the blood), she was short of breath and laboratory test showed evidence of damage to the liver and kidneys. She was treated with the antidote acetylcysteine and had recovered fully by 48 hours. She was fortunate to be taken to the vet and given the antidote very promptly. This case reminds us to store medicine appropriately as kittens (and dogs and children) will chew packets of medication. 

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