| Verdict for dogs | Don't feed |
| Severity | 3 / 5 — Risky — more than a taste can cause real illness. |
| Safe amount | None |
| Category | Nuts |
| Source | ASPCA Animal Poison Control — People Foods to Avoid Feeding Your Pets; Merck Veterinary Manual · reviewed 2026-08-07 · confidence: high |
Two problems. All walnuts are high-fat nuts the ASPCA warns can cause vomiting, diarrhea and pancreatitis. Worse, walnuts — especially old, damp or fallen ones — commonly carry molds that produce tremorgenic mycotoxins, causing tremors and seizures. Black walnut is the one vets warn about most.
Don't feed it. If your dog has already eaten some, call your vet or poison control with the amount and the timing and follow their advice.
Never induce vomiting and never give any medicine unless a vet tells you to — it can do more damage than the poison. What we will and won't tell you.
Can cats eat walnuts? — Don't feed it to cats either.
No — walnuts should not be given to dogs. If yours has already eaten some, call your vet. Two problems. All walnuts are high-fat nuts the ASPCA warns can cause vomiting, diarrhea and pancreatitis. Worse, walnuts — especially old, damp or fallen ones — commonly carry molds that produce tremorgenic mycotoxins, causing tremors and seizures. Black walnut is the one vets warn about most.
Watch for: Vomiting; Diarrhea or loose stools; Loss of appetite; Belly discomfort or unusual tiredness. Some signs lag by a day — call, don't wait.
More than a taste can cause real illness, and the risk rises with the amount and with a smaller pet. The safe amount is none — if your dog has had more, call your vet.