Using an OTC human painkiller for your cat or dog is not a good idea, because you can easily overdose it, if you haven’t got any instruction from your own vet. Tylenol’s active ingredient is paracetamol (INN) or acetaminophen (USAN), which is an antipyretic and anti-inflammatory drug that helps to ease moderate pain.
Why Is Tylenol Toxic To Pets?
Dogs and especially cats have got a very narrow tolerance to paracetamol/ acetaminophen, as their metabolism works different compared to our human metabolism, meaning the drug is being broken down and eliminated from the body much slower, harmful metabolic derivates will effect the canine and feline organs differently. Cats lack a certain enzyme in their liver that is needed to break down this drug, they develop a problem called blood dyscrasia, which is fatal.
How Does Tylenol Effect Cats and Dogs?
Tylenol, or acetaminophen, comes in a variety of strengths and may also be an additive in other medications such as opioids, commonly used for post-operative pain in humans. A typical Regular Strength Tylenol (325mg) can be enough to cause severe symptoms in an average sized cat. Cats are not able to tolerate acetaminophen and can develop liver or red cell damage. In severe cases, methemoglobinemia can develop, which changes the nature of red blood cells and decrease their oxygen carrying capacity in the blood. A type of anemia, known as Heinz body anemia, can also occur and can lead to the destruction of red blood cells within circulation. As a result, vital organs are deprived of oxygen. Dogs do not seem to develop this symptom, rather, they are at high risk for necrosis, or death, of the liver cells.