Paracetamol Poisoning in Dogs

Though paracetamol is not licensed for use in dogs, it is commonly prescribed by veterinarians as an over the counter pain reliever. Accidental poisoning can also occur if your dog gets into a bottle of acetaminophen and ingests several pills. If you suspect that your dog is suffering from paracetamol poisoning, you should seek veterinary attention immediately.

Paracetamol poisoning occurs due to the acetaminophen, which is a common pain reliever that many dog owners will give to their dog. Some dogs are less tolerant to this drug than others.  Dogs that are suffering from paracetamol poisoning will likely be treated with acetylcysteine. In dogs, paracetamol poisoning can occur if they ingest 75 mg per kilogram of body weight or more. Kidney and liver failure can occur from paracetamol poisoning.

Paracetamol poisoning in dogs can be very serious, potentially causing your dog to go into kidney or liver failure. If you think that your dog has ingested a large quantity of paracetamol, you will need to seek emergency veterinary care. Symptoms to watch for include:

• Labored breathing
• Swollen face or neck
• Swelling of the limbs
• Brownish-gray gums
• Hypothermia
• Jaundice
• Vomiting
• Dark urine
• Excessive thirst
• Coma
• Death

For humans, paracetamol, otherwise known as acetaminophen is usually safe to use as a pain reliever. However, for dogs, paracetamol can be deadly when ingested. Toy breed dogs seem to be more susceptible to paracetamol poisoning simply because they are smaller and it takes a smaller dose of paracetamol to cause toxicity. 

Red blood cell abnormalities can occur as well as kidney and/or liver damage. In most cases, kidney and liver damage is not reversible. Ingestion of large doses of paracetamol can also cause coma or death. Quick treatment is essential for your dog’s full recovery without permanent damage to the liver or kidneys.

Your veterinarian will begin by taking your dog’s medical history. This is important, especially if you have had to take your dog to an emergency clinic where the attending veterinarian does not know your dog’s history. If you gave your dog acetaminophen, or paracetamol, be sure to relay to your veterinarian the amount that was given and the time it was given. If you did not give your dog paracetamol but suspect that your dog has gotten into Tylenol or some other acetaminophen, you should let your veterinarian know.

Your veterinarian will conduct a full physical examination and then order a biochemistry panel, complete blood count, urinalysis and fecal examination. These diagnostic tests will help determine the level of toxicity that is currently in your dog’s body. Your dog’s liver and kidney function will also need to be closely monitored to watch for any changes that may mean their liver or kidneys are damaged and failing. 

Once your veterinarian has diagnosed paracetamol poisoning in your dog, they will discuss treatment options with you.

Your dog may require hospitalization and supportive care while undergoing treatments for paracetamol poisoning. Supportive care will likely include supplemental oxygen, intravenous fluid therapy, vitamin C supplementation, cimetidine and N-acetylcysteine. Cysteine is an amino acid that aids in repairing potential damage that has been done to the liver. Other liver protectants include milk thistle and S-Adenosyl-methionine or SAMe. 

The first step in treating paracetamol poisoning in dogs is decontamination, then your veterinarian will do baseline blood work to monitor your dog’s liver and kidney functions to ensure that your dog’s organs are not showing signs of damage. Liver protectants will need to be given as well as supportive care. A gastric lavage may also be done or vomiting induced to rid your dog of any paracetamol that is still in their stomach. Activated charcoal meals may be fed.

Once your dog is able to go home from their stay in the hospital, your veterinarian will still need to monitor the kidney and liver function to ensure that there are no long-term effects of the paracetamol poisoning. When your dog goes home, be sure to follow all care instructions given by your veterinarian to ensure that your dog stays on the road to recovery.

Depending on the amount of paracetamol that your dog ingests, their recovery will be guarded until your veterinarian can see how well your dog is responding to treatment. Your dog’s liver and kidney functions will need to be monitored during treatment and after to ensure that any long-term effects are caught early.

Simply avoid giving paracetamol to your dog, unless it has been prescribed. Keep the tablets out of your dog's reach, and ideally behind a locked door.