Can Dogs Eat Walnuts? NZ Safety Answer

Why

Walnuts present multiple health hazards for dogs. The primary danger comes from mould. Walnuts have a high moisture and fat content, making them highly susceptible to growing *Penicillium* moulds. These moulds produce tremorgenic mycotoxins, such as penitrem A, which are highly toxic to dogs. Ingestion of even a small amount of mouldy walnuts can cause severe neurological symptoms, including muscle tremors, incoordination, and seizures. In addition to the mould risk, walnuts are extremely high in fats and oils. Dogs that consume high-fat foods are at risk of developing gastroenteritis or acute pancreatitis, a painful and potentially fatal disease. Furthermore, the hard shell and large size of walnuts make them a physical choking hazard or bowel obstruction risk. Black walnuts (*Juglans nigra*), which are less common but present in some NZ gardens, are also toxic in their own right.

How much is a problem

English walnuts are not directly toxic like macadamia nuts, but due to the high fat content and mould risks, no walnuts should be intentionally fed to dogs. Even a single mouldy walnut picked up from a garden or compost pile can cause severe mycotoxin poisoning in a dog of any size.

If your dog has eaten it

If your dog ate plain, fresh, food-grade walnuts from the pantry, monitor them for vomiting, diarrhea, or abdominal pain over the next 24 hours. However, if they ate walnuts from outdoors, a compost bin, or moldy walnuts, watch them closely for neurological signs: drooling, agitation, incoordination (walking like they are drunk), muscle tremors, twitching, or seizures. This requires immediate veterinary intervention.

Safer alternatives

If you want to give your dog a healthy treat, use small pieces of carrot, cucumber, or pet-specific treats designed for dogs.

Related reading

• Dog Food Guide NZ
• Pet Emergency Kit NZ Civil Defence Guide
• New Dog Owner: First 30 Days NZ

References

• Pet Poison Helpline, Moldy Food (Tremorgenic Mycotoxins), checked 2026-07-16: https://www.petpoisonhelpline.com/poison/mycotoxin/
• SPCA NZ, Dangerous foods for dogs, checked 2026-07-16: https://www.spca.nz/advice-and-welfare/article/dangerous-foods-for-dogs

When to see a vet

If your dog shows muscle tremors, seizures, or incoordination after eating walnuts (especially mouldy ones), contact your NZ vet or an emergency clinic immediately.

Important notice

*General food-safety information for NZ pet owners, reviewed against ASPCA/VCA guidance (July 2026). For any suspected ingestion or illness, contact a NZ vet, after-hours emergency clinic, or SPCA for advice.*