food
Walnuts
NOT RECOMMENDED
Walnuts can contain mould toxins and cause gut obstruction. Black walnuts are especially toxic.
What to do
Contact your vet if your dog ate mouldy or black walnuts, or is showing symptoms.
When to contact a vet: Emergency vet attention if your dog has tremors or seizures.
Symptoms to look for
- vomiting
- diarrhoea
- tremors
- seizures
- weakness
- lethargy
- abdominal pain
Why
Walnuts are high in fat and can trigger pancreatitis. Mouldy walnuts can contain tremorgenic mycotoxins that cause seizures. Black walnuts are more toxic than English walnuts and can cause severe neurological signs. Whole walnuts can also cause obstruction.
- Substances of concern
- mycotoxins, high fat, obstruction risk, juglone in black walnuts
- Safer parts
- {}
- Parts to avoid
- {"mouldy walnuts","black walnuts","salted walnuts","whole walnuts"}
- Preparation
- Not recommended.
- How much matters
- A few plain English walnuts are unlikely to be fatal, but mouldy or black walnuts are dangerous.
- Severity
- Moderate to severe
Sources
- Pet Poison HelplinePrimary authoritative — Nutrition
This answer rests on a single approved source and is queued for further review.
Information reviewed against recognised veterinary and animal-safety sources. Source organisations are independent of Is It For Dogs unless otherwise stated.
Last reviewed 6 September 2026 · next review due September 2027.
Safety classifications are based on available expert and veterinary information. Individual dogs may react differently, particularly dogs with allergies, existing health conditions or specific dietary requirements.
Important: Is It For Dogs provides general information about the safety of foods, plants, drinks, ingredients and other items around dogs. Our information is based on sources we consider reliable and is intended to help dog owners make informed decisions. It is not a substitute for advice from a qualified veterinary professional. Read more
Dogs can react differently depending on their size, age, health, allergies, medications, the amount consumed and other circumstances. An item classified as Safe is not necessarily suitable for every individual dog.
If your dog has eaten something potentially poisonous or dangerous, has eaten an unknown substance, or is showing concerning symptoms, contact your veterinarian or an emergency veterinary service immediately.
Do not induce vomiting or give your dog medication unless specifically instructed to do so by a veterinary professional.