Why Are Lilies So DangerousWhy Human Painkillers Are Dangerous to Pets for Cats?
Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely used class of painkillers in humans. Dogs and cats have different physiology to human, for cats especially, lacking some of the key enzymes that is important in the metabolism of these medication.
Important: Human painkillers should never be administered to pets unless prescribed by a veterinarian.
Acetaminophen (Paracetamol, Panadol)
Acetaminophen is commonly used in humans to reduce pain and fever. While it has a lower risk of stomach irritation than NSAIDs, it can be highly toxic in pets, especially cats.
In dogs, toxicity is usually only seen with high doses or repeated exposure.
In cats, even small amounts can cause severe problems or even death, including:
● Heinz body anemia (abnormal hemoglobin affecting oxygen transport)
● Methemoglobinemia (blood cannot carry oxygen efficiently)
● Brown or muddy-colored gums
● Rapid heartbeat and breathing
● Swelling of face or paws
● Lethargy and weakness
● Jaundice
● Liver and kidney damage
● Death if untreated
Ibuprofen (Nurofen)
Ibuprofen is commonly used to relieve pain, inflammation, and fever in humans. While sometimes prescribed for dogs in specific veterinary formulations, it has a very narrow safety margin.
In dogs, ibuprofen can cause:
● Vomiting, diarrhea, loss of appetite
● Stomach ulcers or perforation
● Kidney damage
● CNS depression, low blood pressure, seizures, or coma
Cats are even more sensitive, with toxic effects appearing at roughly half the dose that affects dogs. Ferrets are also highly sensitive. Even a single accidental ingestion can be life-threatening.
Treatment of Human Painkiller Poisoning
Immediate veterinary care is essential. Treatment often includes:
● Inducing vomiting (if the ingestion was recent and safe)
● Administering activated charcoal to prevent further absorption
● Providing IV fluids to support kidney function
● Blood transfusions in severe acetaminophen cases
● Medications to protect the stomach and liver
The earlier the treatment, the better the prognosis.
Key Takeaways for Pet owners
● Never give human painkillers to pets.
● Cats are more sensitive than dogs to nearly all painkillers.
● Recognise early symptoms of toxicity—early intervention saves lives.
Reference
Safdar A. Khan, DVM, MS, PhD, DABVT, ASPCA Animal Poison Control Center, Urbana, Illinois
Reviewed/Revised Oct 2020 | Modified Jun 2025