Acetaminophen is an over-the-counter medicine used for pain and fever relief. It’s the active ingredient in a number of medications–you can find it sold alone as Tylenol or in combination with other drugs for multi-symptom relief, like Nyquil or Excedrin. It’s very likely that you have several medications containing acetaminophen in your home, which is why being aware of acetaminophen toxicity is so important.
Most animals don’t metabolize or break down drugs in the same way that humans do. As a result, something that’s safe for humans to ingest can lead to toxicity or death in animals. Acetaminophen is one of those cases. For dogs, a toxic dose is 45 milligrams of acetaminophen per pound of body weight, while the toxic dose for cats is smaller at 22 milligrams per pound of body weight. This means that consuming a single tablet of Tylenol, which contains 325 milligrams of acetaminophen, would be fatal for the average cat or small dog if medical attention is not sought immediately.