VeterUSA · Emergency triage
Did your pet eat ibuprofen or another NSAID?
Covers ibuprofen (Advil, Motrin) and naproxen (Aleve). These human painkillers cause stomach ulcers and kidney damage in pets — and they are never safe to give a dog or cat at home.
Cats are about twice as sensitive as dogs, and naproxen is dangerous at tiny doses. Never give your pet a human pain reliever — and don't wait for symptoms before calling.
Common strengths
- Ibuprofen (Advil/Motrin), OTC200 mg
- Ibuprofen, prescription400–800 mg
- Naproxen (Aleve), OTC220 mg
- Naproxen, prescription250–500 mg
Naproxen has a long half-life and is dangerous at very small doses — when in doubt, treat it as urgent.
Both helplines are staffed 24/7 by veterinary toxicologists. A consultation fee may apply. If your pet is vomiting (especially with blood), very weak, or having seizures, skip the calculator and go to the nearest ER now.
How ibuprofen and NSAID poisoning works
Ibuprofen and naproxen block enzymes (COX) that protect the stomach lining and maintain blood flow to the kidneys. In pets, that leads to stomach and intestinal ulcers, then kidney injury, and at high doses, neurological signs and seizures. Pets — especially cats — clear these drugs much more slowly than people, so a "normal" human dose can be a serious overdose for them.
When to worry (ibuprofen, dogs)
Veterinary references put dogs at risk of stomach ulcers around 25–125 mg per kg of body weight, kidney failure around 175–300 mg/kg, and neurological signs above ~400 mg/kg (with doses over ~600 mg/kg potentially lethal). For scale, two 200 mg tablets is already ~40 mg/kg for a 20 lb (9 kg) dog.
Cats and naproxen are far more dangerous
Cats are roughly twice as sensitive as dogs and have no safe NSAID dose. Naproxen is much more potent than ibuprofen — toxicity is reported at doses as low as ~5 mg/kg in dogs — and its long half-life means it lingers. Treat any cat exposure, or any naproxen exposure, as urgent.
Is this calculator a substitute for a vet?
No. It estimates urgency from established thresholds, but individual pets vary. For any cat, any naproxen, or any uncertainty, call a veterinarian or an animal poison control line rather than wait.