Can Cats Eat Black Walnuts?

With limitsMild effects expected
Verdict for cats: Caution · Evidence: M · Last verified: 2026-11-01 (seed data — veterinary review pending)

Only in small amounts, prepared the right way. Black Walnuts is not poisonous to cats, but it has real downsides. It contains mold toxins and juglone (dogs are the documented species). Follow the limits below and watch for stomach upset.

Why only in moderation

mold toxins · juglone (dogs are the documented species)

Which parts are the problem?

shells

Dose & exposure rules

A single fresh kernel unlikely to harm; moldy nuts are the risk

If it must be on the menu: safe preparation

None recommended

Symptoms to watch for

GI upsettremors (moldy)

Hours

What to do now

Vet if moldy nuts were eaten

✔ Reviewed against ASPCA. Veterinary review pending — this page will carry a named, licensed veterinarian's sign-off after review (see team and editorial policy). General information only, not veterinary advice.

FAQ

How much black walnuts can a cat eat?

A single fresh kernel unlikely to harm; moldy nuts are the risk

What are the signs of black walnuts problems in cats?

Watch for: GI upset; tremors (moldy). Hours

What should I do if my cat ate black walnuts?

Vet if moldy nuts were eaten

Related:

Can dogs eat black walnuts?

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