Acetaminophen Toxicity in Dogs

Acetaminophen, also known as paracetamol or Tylenol, is a popular over-the-counter medication used to control pain and fever in people. It can cause toxicity in dogs, which is unfortunately relatively common due to it being a staple in many medicine cabinets. Acetaminophen comes in various forms, including tablets, capsules, liquids, and gel caps. It may be the only ingredient in a medication or be part of a multi-symptom product used to treat headaches, colds, and other conditions. 

Low doses of acetaminophen are occasionally recommended by veterinarians but should only be given under their guidance due to the risk of toxicity. All accidental ingestions require immediate veterinary advice. 

Within 1 to 4 hours of ingesting acetaminophen, a dog may show signs such as: 

• Panting
• Vomiting 
• Drooling
• Rapid breathing 
• A high heart rate
• Depression
• Weakness
• Abdominal pain
• Refusing to eat
• Brown or blue mucous membranes 
• Swelling of the face, paws, and forelimbs

Acetaminophen can cause liver damage, which may be delayed for up to a week. If this happens, a dog may also show the following symptoms: 

• Jaundice
• Dark urine
• Discolored stools
• An enlarged abdomen
• Increased drinking and urination

Acetaminophen is commonly found in households with companion animals. The cause of acetaminophen poisoning in dogs is from the accidental ingestion of acetaminophen, usually from when a dog gets into their human’s medications or when a pet parent tries to treat their dog’s pain at home. Because dogs metabolize drugs differently than humans, even a small piece of a tablet can lead to toxicity, especially with young and small dogs who are at higher risk.

Diagnosis is most often made in dogs who have a known or suspected exposure to acetaminophen and are showing signs of illness. It is not common to test for acetaminophen levels in the blood; not only is it usually done at a human hospital or specialized laboratory, but the results may also take a while to come back. Therefore, vets primarily rely on information from the pet parents to diagnose acetaminophen toxicity. 

Be prepared to provide your vet with information such as the amount ingested, the timing of the ingestion, and the type and strength of the medication. Taking the bottle and remaining pills with you can be helpful as well. 

If your dog is showing symptoms of poisoning, your vet may do a physical exam, followed by blood and urine tests to see what may have been ingested. Depending on how serious your dog's condition is, your vet may begin therapy immediately before the cause is known. 

The sooner a dog is decontaminated and treated for acetaminophen poisoning, the better the prognosis.

Detoxification

Medications

Supportive care

Additionally, the dog may receive fluids intravenously, as well as vitamin C, liver protectants, and other medications to help flush out toxins as well as support the system. Liver supplements can be started. Dogs who suffer from liver damage may require vitamin K, dextrose, and plasma transfusions. Those who develop anemia or methemoglobinemia may need a blood transfusion or oxygen supplementation.

Recovery from acetaminophen toxicity depends on various factors, including the dog’s health, how much acetaminophen they ingested, and how soon they received treatment. Some dogs may develop permanent liver damage, but those who receive early treatment are less likely to suffer from any long-term effects. 

It may be necessary to monitor a dog’s liver enzymes for several days to weeks after being sent home. Most dogs will need to continue taking liver protectants for weeks. 

Got more questions about acetaminophen toxicity in dogs? Chat with a vet professional today to learn more about acetaminophen toxicity.

The cost of treating acetaminophen toxicity can vary depending on how serious the condition is. Pet parents can expect to spend $300 to $500 for a vet visit to induce vomiting and $600 to $1,700 for a short hospitalization.