PupkeeperToxicEmergency
Is black walnut toxic to dogs?
Toxic. Moldy black walnuts and hulls can cause tremors and seizures, and chewing the wood shavings can make dogs wobbly.
If your dog ate or touched this, call your vet or a pet poison line now
United States
Poison lines in other countries: United Kingdom, Australia, Canada, New Zealand
What to do now
- Call your vet or a pet poison line now.
- Take away any walnuts, hulls or shavings.
- Tell the vet if the nuts looked moldy.
Don't
- Don't make your dog vomit unless a vet tells you to.
- Don't give milk, oil, salt or other home remedies unless a vet tells you to.
Signs to watch for
- Vomiting
- Drooling
- Agitation
- Wobbly walking
- Tremors
- Seizures
When signs appear: Tremors from moldy nuts can start within 1-2 hours
Why
Mold on the nuts and hulls can make tremor-causing toxins (mycotoxins). Black walnut's own toxic substance is not known.
Sources
- ASPCA Animal Poison Control: Black Walnut
- Pet Poison Helpline: Moldy Food (Mycotoxins)
- Merck Veterinary Manual: Tremorgenic Neuromycotoxicosis in Dogs
Guide reviewed 9 October 2026.
General information from the sources above, not a diagnosis. When in doubt, call your vet.