Food safety · 2 min read

Can cats eat Walnuts?

No — dangerous

No. Walnuts contain juglone and are prone to mould that produces tremorgenic mycotoxins — both are dangerous to cats. The high fat load also raises pancreatitis risk. Don't feed, and keep walnut trees' fallen nuts away from outdoor cats.

If your cat has just eaten walnuts

  1. Move your cat away from the walnuts.
  2. Don't induce vomiting at home — this is dangerous in cats.
  3. Call your vet or out-of-hours emergency vet immediately.
  4. If you can't reach a vet, call the Animal PoisonLine on 01202 509000 — 24/7, charges apply.
  5. Note how much walnuts was eaten, when, and your cat's weight.

What's the full picture?

Walnuts are more dangerous than most culinary nuts because of juglone (a toxin produced by the tree) and the ease with which walnuts develop mould during storage. Mouldy walnuts can cause tremors and seizures in cats.

Cats don't often seek out walnuts, but will chew on them if they find one on the floor or play with them as batting toys. Cracked or mouldy walnuts are the most dangerous.

Owners with walnut trees should clear fallen nuts regularly — these can mould quickly in British weather and be picked up by outdoor cats.

Symptoms to watch for

0–12 hours
Vomiting, restlessness, tremors (if mouldy), diarrhoea.
12–72 hours
Pancreatitis signs, liver injury in rare severe cases.

If you're worried right now

Call your vet or out-of-hours emergency vet first. For poison advice, the Animal PoisonLine (UK) is on 01202 509000 — 24/7, charges apply. Your vet can also call the Veterinary Poisons Information Service (VPIS) directly.

Almonds caution Macadamia nuts no Peanut butter caution

About this guidance

Every entry on this site is compiled from published UK veterinary toxicology sources — International Cat Care, Veterinary Poisons Information Service (VPIS) references, RCVS-registered practice materials, and peer-reviewed feline medicine literature. Where the evidence is mixed, we err on the cautious side because cats are unusually sensitive to many common substances that are harmless to humans and even to dogs.

This is general information written for UK cat owners. It is not personalised veterinary advice for your specific cat, their age, weight, medical history, or the exact exposure you're dealing with. If your cat has eaten something or is unwell, call your vet first. The Animal PoisonLine on 01202 509000 is available 24/7 for a small fee and can tell you whether an emergency visit is needed.

Entries are reviewed and updated as new research emerges. Spotted an error? Let us know — corrections are investigated and applied within 24 hours. For more context on how we work, see about and our full disclaimer.

Last reviewed: · By the What Can My Cat Eat? editorial team

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