Is English Walnut 'Pedro' toxic to cats?

Yes — english walnut 'pedro' is toxic to cats according to the ASPCA. Keep it well away from any cat that chews plants; reactions can be significant. The ASPCA lists Black Walnut (Juglans nigra), the same genus, as toxic to dogs and horses (non-toxic to cats), with laminitis and colic in horses and tremors and seizures in dogs from moldy nuts and hulls. 'Pedro', as Juglans regia, contains juglone throughout, and dropped nuts readily grow Penicillium mould producing tremorgenic mycotoxins (Penitrem A) dangerous to dogs. Treat as toxic: keep fallen nuts and hulls away from dogs and horses and contact a vet if ingested.

The ASPCA lists Black Walnut (Juglans nigra), the same genus, as toxic to dogs and horses (non-toxic to cats), with laminitis and colic in horses and tremors and seizures in dogs from moldy nuts and hulls. 'Pedro', as Juglans regia, contains juglone throughout, and dropped nuts readily grow Penicillium mould producing tremorgenic mycotoxins (Penitrem A) dangerous to dogs. Treat as toxic: keep fallen nuts and hulls away from dogs and horses and contact a vet if ingested. Signs usually appear soon after chewing rather than hours later — watch for drooling, pawing at the mouth, vomiting, loss of appetite, or unusual lethargy after your cat has had access to english walnut 'pedro'.

Stay calm. Remove any plant from your cat's mouth and take the plant away. Note how much was eaten and when, and do not induce vomiting unless told to. Call your vet or the ASPCA Animal Poison Control Center on (888) 426-4435 and follow their advice; a leaf or photo helps the vet treat it correctly.

The ASPCA classification Growli uses applies to both cats and dogs: English Walnut 'Pedro' is toxic to dogs as well. See the full english walnut 'pedro' pet-safety guide for both species.

For a similar look without the risk, see the best cats-safe plants list — every plant there is ASPCA non-toxic to cats and dogs.