Is naproxen toxic to dogs?
Naproxen (Aleve) is a common painkiller that is far more dangerous for dogs than for people because dogs eliminate it very slowly. Even one tablet can cause stomach ulcers or kidney damage. The toxic principle is a long-acting NSAID that blocks protective prostaglandins in the stomach and kidneys.
Toxic dose by dog weight
Naproxen can cause serious gastrointestinal ulceration and kidney injury in dogs. This reference does not establish a verified single safe numeric threshold. Tablet strengths and repeated exposures differ; contact a veterinarian after any suspected ingestion rather than calculating a home severity tier.
Symptoms timeline
0–2 hours: often no signs yet, vomiting.
2–12 hours: vomiting blood, loss of appetite, abdominal pain.
12–72 hours: black tarry stool, increased thirst and urination, kidney failure, stomach perforation.
Days later: stomach ulcers and kidney injury can develop 1–5 days after eating. If in doubt, call your vet.
Go to the vet / call ASPCA Animal Poison Control (888) 426-4435 now if…
- Your dog ate any naproxen (Aleve) tablet
- There is vomiting with blood or black stool
- You are unsure what or how much your dog ate
- Your dog is very young, old, pregnant or has heart, liver or kidney disease
First aid: do's and don'ts
Do:
- Move your dog away from the source and remove any remaining material from their mouth if it is safe to do so
- Keep the packaging, label or a sample/photo of what was eaten
- Note your dog's weight, the approximate amount and the time of ingestion
- Call your vet or a pet poison hotline right away
Don't:
- Never induce vomiting without veterinary advice — for some substances it causes more harm
- Don't give salt, hydrogen peroxide, oils or home remedies unless a vet tells you to
- Don't wait for symptoms if the substance is highly toxic
- Don't give human medicines to treat symptoms
How vets treat naproxen exposure
Treatment depends on the amount, time since ingestion and your dog's signs. It may include decontamination when appropriate, activated charcoal for some toxins, IV fluids, medications to control signs, and monitoring. Bring the packaging so your vet can tailor treatment.
Prognosis
Most dogs treated early do well. The outlook depends on the dose, how quickly care begins, and your dog's overall health. Severe or delayed cases carry a more guarded prognosis.
What to do now
Call your veterinarian or an animal poison-control service for exposure-specific advice. Dog poison control: phone numbers, fees and when to call.