Can Dogs Eat Walnuts? How safe is it?

Can Dogs Eat Wallnuts - Anydoggie

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The other day, while enjoying my breakfast, which consists of a healthy mix of seeds, fruits, and walnuts, I started wondering: Can dogs eat walnuts? 

Jo, my fluffy-puff Welsh Corgi, was peacefully laying next to me, waiting for some bits to fall (because you never know!). So I thought to myself, would it be safe if she ate a walnut? I heard somewhere that some nuts could be toxic to dogs, and I decided to do some research to find out:

There are many risks associated with dogs eating walnuts, and that’s why it is not safe to let your dog eat them. If the walnuts are old and moldy, the mold produces toxin called tremorgenic mycotoxin. It is poisonous to dogs, can cause a lot of complications, and can also be lethal, especially for small dogs. 

To learn more about why walnuts are not a safe treat, what the symptoms of eating a moldy walnut are and what to do if your dog eats a moldy walnut, keep reading:


Why Shouldn’t Dogs Eat Walnuts?

You might have heard that walnuts are very nutritious, for us, humans. They have been part of our diet for thousands of years. They provide us with a lot of health benefits. They are rich in “good” fats, such as omega-3, they are full of antioxidants, can improve the health of our brain, prevent heart diseases and cancer. 

Then, you would think that dogs can eat walnuts as well. They would surely benefit the same as we do. Sadly, it’s not that simple.

There are a few main reasons why your dog shouldn’t eat walnuts:

Mold producing Tremorgenic MycotoxinThe risk of eating a walnut which is infected by mold producing a toxin is quite high
High Amounts of FatThe high amounts of fat may cause vomiting, diarrhea, and pancreatitis
Size of the WalnutsThey are quite big nuts and can get stuck in the dog’s digestive system, particularly for the small dogs

Keep reading:

Tremorgenic Mycotoxin is Poisonous to Dogs

The most significant risk associated with dogs eating walnuts is when they eat old, wet, and moldy walnuts, affected by mold. It produces a toxin called tremorgenic mycotoxin. 

Fungi, which produce tremorgenic mycotoxin, grow on a wide variety of foods:

  • Nuts fell on the ground or improperly stored nuts
  • grains and grain-containing products, like bread
  • dairy, like cheese
  • other food byproducts

Be careful, because it is not only toxic to dogs but other animals and humans, too. 

If the dog eats an infected nut, the Tremorgenic Mycotoxin affects the nervous system, brain, liver, and kidneys in a very short time. It causes convulsions, seizures, tremors, and, if not treated immediately, can be lethal, especially for small dogs. 

Walnuts which you can find on the ground, in your garden, in the parks and during the walks with your dog, are at the highest risk of being infected by the toxic mold. 

If you live in the area with a lot of walnut trees, mainly when they are in the season (September and October), be vigilant when out walking with your dogs. They sometimes don’t distinguish what they munch on!

Walnuts are High in Fats which is Not Good for Dogs

Walnuts, like any other nuts, and seeds have a very high percentage of fats. Walnuts are made up of 65% fat. 

Daily recommended allowance of fat for your dog varies depending on if she is a puppy (21g), adult (14g), pregnant (29g) / nursing dog (67g). You can see it’s quite a small amount of fats, and even a single walnut can increase the daily intake quite a bit.

If your dog overeats fat, she can vomit, get diarrhea. If unchecked for a longer time, she can develop pancreatitis. It’s undoubtedly something you would not want your dog to experience.

There are many more suitable treats you can give your dog to munch on instead of walnuts.

Walnuts are Quite Big and can Get Stuck in Dogs’ Digestive Tract

Walnuts are quite big nuts, and especially the small dogs can have a problem digesting them if they don’t chew them properly. 

That’s why it’s a good thing not to feed your dog with walnuts at all. You should also check on your dog if she eats a walnut that falls accidentally or while you are out walking them.

Did You know There are Two Types of Walnuts?

black and english walnuts for small dogs

There two most common types of walnuts:

They are the English walnut and the Black walnut. The English walnut originated in Iran (Persia), and the Black walnut is native to the eastern USA and Canada. 

The English walnut and its hybrids are grown commercially all over the world because of their favorable hulling characteristics.

In contrast, the Black walnuts, despite being known for their unique flavor, are very hard to shell. They mostly grow naturally in the parks, on the streets, and in the woods without much harvest from people. 

That’s why the black walnuts (and actually any naturally grown walnuts) are the ones that are the riskiest to your dog. They fall to the ground during September and October every year, get infected by mold during the wet autumn months, and there is a big chance your dog munches on them while sniffing around. 

You should be extra cautious when walking out with your dog during autumn, winter, and early spring. 

Can Dogs Eat Walnuts if they are processed?

Walnuts are typically sold either as a snack or as an ingredient in candies, cereals, and baked goods. As a snack, you can get them shelled or unshelled, and as an ingredient, you can get them shelled, ground, crushed, or as oil. 

The processing of walnuts ensures that there is no mold, and they keep fresh as long as naturally possible. It then depends on your storage conditions if they remain fresh and remain harmless. For example, we store shelled walnuts in the freezer, so they stay fresh for a long time.

Because of the above reasons, the dogs can eat processed walnuts in small amounts. Provided they are fresh, unspoiled, and you haven’t noticed any mold on them.

Can Dogs Eat Walnuts if you bake them first?

baked walnuts for dogs

Hmm, that yummy taste of roasted walnuts, when you bake them on top of cakes and cookies. They get crispy and have this unique taste. 

The baking/roasting process should ensure that all the harmful germs get killed. However, as a rule of thumb, you should dispose of any walnuts that look harmful before using them for baking. Mainly when you are using walnuts, you harvested from your garden or a park.

Yet again, the dogs can eat walnuts that are baked first, however only in small amounts. Provided they were fresh, unspoiled, and you didn’t notice any mold on them before baking.

What happens if My Dog eats a Walnut?

You don’t need to panic if your dog eats a walnut. Generally speaking, your dog shouldn’t have any side effects, if she eats a small number of walnuts (one to three) that are fresh and unspoiled. 

If you bought a bag of walnuts and some of them fall on the ground, you don’t need to worry. They are processed and sealed in a protective atmosphere, so there is a good chance they are unspoiled.

If you notice that your dog ate walnuts fallen on the ground, the best thing to do is to examine the rest if they are moldy. You will usually notice they look unhealthy. Keep reading to see how a moldy walnut looks like:

How do I know if my dog eats a moldy walnut? What are the symptoms?

If you live in an area with a lot of walnut trees and you don’t walk your dog on a lead, you should be extra careful. Particularly during autumn, winter, and early spring.

The best practice would be not to leave your dog alone after such a walk for an extended period because the symptoms of intoxication show in a short time. The ability to rush them to the vet can help to save their life. 

The symptoms of eating a moldy walnut for a dog can include the following:

  • Lethargy
  • Shivers/tremors/seizures
  • Unsteadiness and lack of coordination
  • Uncontrolled drooling
  • Vomiting
  • Diarrhea

What Should I Do When My Dog Eats a Moldy Walnut?

If your dog eats a moldy walnut, you should immediately call and visit a vet. Don’t wait for the symptoms to develop.

You will know that the walnut is moldy when its shell and inner flesh are dark. They will look unhealthy, like in the image below:

moldy and fresh walnuts

Be particularly careful when you walk your dog in the area with a lot of walnut trees during autumn, winter, and early spring. 

Can a Walnut Kill a Dog?

If your dog eats a small number of walnuts that are fresh and unspoiled and chews on them well, there is a minimal chance she dies. Unless she has a severe allergic reaction. In such a case, you need to rush her to the emergency vet immediately. 

If, however, your dog eats moldy walnut, you should rush her to the emergency vet as soon as possible. It may save her life! Generally, smaller dogs tend to be affected by the mold intoxication much more than the bigger dogs.  


After doing this research, I concluded that if Jo (my Welsh Corgi) eats a walnut that accidentally fell from the table, it’s all good. No need to worry. After all, I am eating them as well. It’s just that I won’t give her walnuts as treats. 

However, when we go for a walk, I will make sure to watch out for those walnut trees. I will better adjust our walking routes. Oh, and I can’t also forget about my parents bringing walnuts from their garden. We usually use them for baking cakes, but still, I remember some of them didn’t look that good! It’s better to be safe than sorry.

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