Last reviewed against current US veterinary guidance in April 2026

Can dogs eat aleve (naproxen)?

Toxic — emergency

Naproxen (Aleve) is more dangerous than ibuprofen for dogs because it stays in their system much longer. Even one tablet can cause severe ulcers and kidney damage. Emergency always.

If your dog has just eaten aleve (naproxen)

Do this now

  1. Call your vet or ASPCA (888) 426-4435 immediately
  2. Bring the bottle — strength varies (standard 220 mg, prescription up to 500 mg)
  3. Do NOT induce vomiting without vet instruction
  4. Emphasize to your vet this is NAPROXEN not ibuprofen — longer monitoring needed
  5. Expect multi-day hospitalization for significant ingestion
  6. Watch for: vomiting, black tarry stool, refusing food, weakness, decreased urination

What your vet will want to know

Have this information ready when you call:

  • Exact strength (220 mg OTC, 375-500 mg prescription)
  • Number of tablets
  • Time of ingestion
  • Your dog's weight
  • Any vomiting or symptoms

The full picture

Naproxen is the most dangerous common OTC NSAID for dogs — not because the initial toxicity is higher than ibuprofen, but because it has a dramatically longer half-life in dogs (74 hours vs humans' 12-17 hours). This means damage accumulates for days after a single dose. Toxicity profile is similar to ibuprofen: severe stomach ulcers, intestinal perforation, acute kidney injury, potential liver damage. But the extended action means vets often need to monitor for 4-7 days after exposure, not 24-72 hours as with ibuprofen. A single 220 mg Aleve tablet can cause serious ulcers in a 50 lb dog. Smaller dogs can be severely poisoned by half a tablet. There is absolutely no reason to give naproxen to a dog under any circumstances.

Should you induce vomiting at home?

Only your vet should make this call. If you can't reach them, our 4-gate safety checker walks through when hydrogen peroxide is appropriate (and when it's dangerous — sharp objects, caustics, certain breeds, and more).

Check if vomiting is safe →

Where aleve (naproxen) hides

Aleve (naproxen) can turn up in foods you wouldn't expect. Check for it in:

  • Aleve (220 mg standard)
  • Aleve PM (contains naproxen + diphenhydramine)
  • Generic naproxen
  • Prescription naproxen (up to 500 mg)
  • Some menstrual pain products
  • Midol Extended Relief

Risks to watch for

  • Severe GI ulcers (longer-lasting than ibuprofen)
  • Intestinal perforation
  • Acute kidney injury (often irreversible)
  • Liver damage at high doses
  • GI bleeding
  • Long damage duration due to 74-hour half-life

Symptom timeline

Symptoms typically progress in stages. Knowing what to expect helps you act fast:

  1. 2–12 hours Vomiting, abdominal pain
  2. 12–48 hours GI ulcers: bloody vomit, melena (black stool)
  3. 2–5 days Extended damage window: kidney injury, continued GI effects
  4. 5–7 days Late complications; monitoring still important

Breed-specific warnings

  • Small dogs fatally poisoned by single tablet.
  • The extended half-life makes naproxen especially dangerous for dogs with pre-existing kidney issues.

Safe portion size

None ever.

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Safer alternatives

  • Dog-specific prescription NSAIDs only

Common questions

Why is naproxen worse than ibuprofen for dogs?

Half-life. Ibuprofen clears in about 6-12 hours in a dog; naproxen takes 74 hours. This means a single dose causes damage for much longer, and repeat doses accumulate catastrophically.

My dog ate half an Aleve — is that an emergency?

Yes. Even 100 mg can cause serious ulcers in a medium dog, and smaller dogs face immediate kidney risk. Call your vet immediately.

How is naproxen treated?

Similar to ibuprofen — IV fluids, GI protectants, monitoring kidney and liver — but for a LONGER period. Expect 3-5 days of hospitalization for significant ingestion. Cost: $2,000-$6,000+.

Are there any veterinary uses for naproxen?

Essentially none. Dog-specific NSAIDs have much better safety profiles and are always preferred. No legitimate reason exists to give a dog naproxen.

Unexpected vet bills can run into thousands

One emergency visit for food poisoning can cost $500–$10,000+. Compare US pet insurance in 60 seconds.

Learn about vet costs & insurance →

Sources

The information on this page is compiled and cross-checked against these authoritative US veterinary and toxicology sources:

Specific toxicity thresholds cited on this page come from the above sources; where they disagree, we cite the more conservative figure. Numbers are general guidance — individual dogs vary in sensitivity based on age, breed, medications, and health conditions. When in doubt, always call your vet.

Spot an error? Report it Last verified: April 2026

Checked against US veterinary guidance — see our editorial standards and source list. If your dog has eaten something and you need urgent advice, call a vet or the ASPCA Animal Poison Control Center on (888) 426-4435.

Important: This page is general information, not veterinary advice. Every dog is different, and individual factors (age, breed, health conditions, medications) can change what's safe. If in doubt, always contact your vet — or the ASPCA Animal Poison Control Center on (888) 426-4435 in the US.