Can Dogs Eat Walnuts?

Walnuts are not a good treat for dogs. Plain store-bought walnuts are unlikely to hurt a dog if it eats one or two, but they can upset the stomach. Black walnuts and moldy walnuts are the real danger. They can cause vomiting, tremors, and seizures.

Why are walnuts bad for dogs?

There are four main problems, according to the AKC and other veterinary sources:

• Mold. Walnuts can grow mold, especially after they fall and get damp. Some molds make poisons that affect the nervous system.
• Black walnuts. The AKC calls these extremely toxic to dogs.
• Fat. Nuts are very rich. Too many can cause pancreatitis, which is a painful swelling of the pancreas, an organ that helps digest food.
• Choking and blockage. Hard shells and whole nuts can choke a dog or get stuck in the gut.

Are moldy walnuts dangerous for dogs?

Yes. This is the biggest risk. The Merck Veterinary Manual lists walnuts as one food where mold can make “tremorgenic” toxins, which are poisons that make the body shake. Pet Poison Helpline says these toxins are also found in moldy bread, cheese, and other rotting food.

Signs can start within 1 to 2 hours, or take several hours. Look for:

• Vomiting
• Shaking or tremors
• Walking as if drunk or wobbly
• Restlessness
• High body temperature
• Seizures

Pet Poison Helpline says signs can last 24 to 48 hours. Merck says most dogs recover in days to weeks, but some dogs have wobbly walking for months or years afterward. Severe seizures can be deadly.

Don’t let your dog eat walnuts that have fallen on the ground, and pick up old nuts in your yard.

Are black walnuts toxic to dogs?

Yes. The AKC says black walnuts contain a chemical called juglone that can cause an upset stomach, vomiting, and diarrhea. It says signs can get worse fast and the nuts could be fatal, so see a vet right away.

The ASPCA lists black walnut as toxic to dogs. It says moldy nuts and hulls can cause tremors and seizures. It also says wood shavings from the tree can cause wobbly walking. The ASPCA notes that the exact toxic ingredient is unknown.

How many regular walnuts can a dog eat?

The AKC says a dog that eats one or two English walnuts, the kind sold in grocery stores, is unlikely to be harmed. Still, it calls them “not the best choice” and says to avoid them. More than a handful may cause pancreatitis.

Signs of pancreatitis include loss of appetite, vomiting, weakness, belly pain, dehydration, and diarrhea, according to the Merck Veterinary Manual. Call your vet if you see these.

Salted walnuts and walnuts with onion or garlic seasoning are toxic, the AKC warns. Walnuts in baked goods may have other ingredients that are harmful, so check labels.

What to do if your dog ate walnuts

1. Take away any nuts and shells your dog still has.
2. Check the type. Was it a black walnut, a moldy one, a salted one, or a plain one?
3. Call your vet or a poison hotline if it was black, moldy, or in a shell, or if your dog ate more than a few.
4. Watch for signs like vomiting, shaking, or wobbly walking. Go to an emergency vet right away if you see them.

Treatment for mold poisoning can include medicine to stop tremors and seizures, fluids, and charcoal to soak up toxins, according to Merck and Pet Poison Helpline.

Other kinds of walnut

Is walnut oil okay for dogs?

We could not find walnut oil discussed in the veterinary sources we read, so we can’t give a firm answer. We do know that the fat in walnuts is one reason they can cause pancreatitis. Walnut oil is pure fat. Ask your vet before you add it to your dog’s food, and don’t give it as a treat.

What about a single walnut?

One plain, shelled English walnut is unlikely to cause harm, per the AKC. Don’t offer it on purpose. If it was black, moldy, or still in the shell, call your vet.

Safer treats to try instead

Plain blueberries, apple slices with no seeds or core, and banana are better choices. See our guides on apples and bananas. Treats should stay under about 10% of your dog’s daily food. For more foods to avoid, see foods that are toxic to dogs.