What is Tylenol and How does it work in dogs
Tylenol is a medication primarily used to treat fever and pain, and secondarily for the treatment of headaches, cough, cold, influenza and allergies. The active ingredient of this medicine is acetaminophen (also known as paracetamol). [1, 2]
Acetaminophen works by blocking the chemicals responsible for transmitting pain signals and inducing fever. However, unlike similar medications like aspirin and ibuprofen, it does not have any anti-inflammatory properties. 
Is Tylenol Safe for Dogs
The FDA does not approve the use of Tylenol in animals. 
Veterinarians may prescribe very low doses of Tylenol (Children’s Tylenol or Infant’s Tylenol) for dogs, often for pain management after a surgery.
However, do not give your dog Tylenol unless prescribed as it may even turn out to be potentially fatal. [5, 6, 7]
Dosage for Dogs
Dosage may vary depending on your dog’s size, weight, age as well as overall health and medical history. Never exceed the dose prescribed by the vet.
Signs of Overdose
In case you have exceeded the prescribed dose or your dog accidentally ate some Tylenol, look out for the following symptoms of an overdose:
- Face and paw swelling
- Blue or brown gums
- Lack of appetite
- Labored breathing
- Black tarry stool
- Jaundice [3, 9]
Immediately contact your vet or call the Animal Poison Control Center Helpline (1-888-426-4435) if you observe any of the above signs.