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Toxic

Are acorns and oak toxic to dogs? Yes: toxic

Toxic. Acorns can cause vomiting, diarrhea and stomach pain, and whole acorns can block the gut; long-term harm is rare in dogs.

If your dog ate or touched this, call your vet or a pet poison line now

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Acorns and oak and dogs: key facts

Verdict
Toxic · Call your vet or a poison line
What it can do
Vomiting, diarrhea, stomach pain, restlessness and swelling around the eyes and mouth. All 6
How fast
Within hours
What to do now
Call your vet or a pet poison line now. All steps
Sources
Dogs Trust, PDSA, ASPCA. Reviewed 9 October 2026.

What should I do if my dog ate acorns and oak?

  1. Call your vet or a pet poison line now.
  2. Take any acorns away from your dog.
  3. Keep your dog on a leash where acorns have fallen.

Don't

  • Don't make your dog vomit unless a vet tells you to.

Symptoms to watch for

  • Vomiting
  • Diarrhea
  • Stomach pain
  • Restlessness
  • Swelling around the eyes and mouth
  • Collapse

When signs appear: Within hours

Why

Acorns contain tannins (tannic acid), which irritate the gut and can affect the liver and kidneys. Green, unripe acorns are more toxic.

Sources

Guide reviewed 9 October 2026. Page updated 7 November 2026.

General information from the sources above, not a diagnosis. When in doubt, call your vet.