The Facts

• In humans, most of the acetaminophen dosage consumed is broken down into nontoxic components by enzymes in the liver and then eliminated as waste. A smaller portion of acetaminophen is broken down into a more harmful substance that can cause liver damage in cases of overdose (or when combined with alcohol).
  Unlike human livers, however, a cat's liver is unable to break down most of any ingested acetaminophen into safer components; instead, toxic substances form that cause serious damage to the liver and blood cells, as well as other cells of the body.
  
  

Misconceptions

• There is a widespread and dangerous misconception that acetaminophen can be safely given to cats as long as it is given in a very small dose. There is no safe acetaminophen dose for cats; even very small amounts can cause illness and, in some cats, death. A report for the ASPCA by Jill Richardson DVM confirmed that signs of toxicity have occurred in doses as small as 10 mg per kg.
  
  

Time Frame

• Acetaminophen poisoning can occur rapidly, within hours following ingestion. Death may occur within hours or days. The time that elapses between ingestion and symptoms of poisoning depends on the amount of acetaminophen ingested and the size and general health of the cat.
  There are treatments for this poisoning but treatments are most effective if started as soon after acetaminophen ingestion as possible. The sooner a cat receives veterinary care, the better her chance of survival.
  
  

Identification

• Acetaminophen is called paracetemol in most countries outside the United States. The most well-known, over-the-counter, medicine brand containing acetaminophen (in the United States) is Tylenol.
  Acetaminophen, as a main ingredient, is usually found in tablet form. Some cold/flu remedies also contain acetaminophen.
  
  

Effects

• Cats with acetaminophen toxicity are often lethargic. As the cat becomes more dangerously ill, she may drool, pant and her heart may beat very fast. The cat may vomit and swelling of her face and limbs may occur. Unusual gum color is also common---the gums may be very pale, or they may be unusually dark. If left untreated, acetaminophen poisoning causes coma and death.