Naproxen and Pets

Naproxen (Aleve, Naprosyn) is extremely toxic to both dogs and cats and should never be given to pets. It belongs to a class of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs) that are used safely in humans but have a very narrow safety margin in animals. Even a single tablet or small dose can cause life-threatening stomach ulcers, gastrointestinal bleeding, kidney failure, and death.

Pets are most often exposed by eating dropped pills, chewing through medication bottles, or being given naproxen by well-meaning owners who mistake it for a safe pain reliever. Cats are especially vulnerable because their bodies cannot efficiently metabolize NSAIDs, and dogs can suffer serious toxicity even at low doses. The risk is especially high if naproxen is combined with other medications or if the animal has underlying health issues.

Symptoms of naproxen poisoning may include vomiting, diarrhea (sometimes with blood), black tarry stools, abdominal pain, lethargy, loss of appetite, increased thirst and urination, weakness, seizures, and collapse. Some signs may appear within a few hours, while others—such as kidney damage—can take days to develop.

Prevention is critical: store all human medications in secure cabinets out of reach of pets, never give your pet any over-the-counter pain medication without veterinary guidance, and consult your veterinarian for safe, pet-approved pain management options. If you suspect your dog or cat has ingested naproxen, seek emergency veterinary care immediately.