You were eating walnuts, and your dogs was eyeballing your food. Or maybe you dropped one on the floor, and your canine scooped it up before you could retrieve it.
Can dogs eat walnuts? Walnuts themselves are not necessarily bad for dogs based on the nutritional content of the walnut itself, but they are often infected with fungi that make them toxic to dogs. If dogs eat walnuts infected with fungi, they can experience vomiting, tremors, or seizures.
Let’s take a look at why tiny amounts of walnuts can be okay, but we recommend avoiding them altogether
The Facts About Walnuts
- Walnuts are highly nutritious. They are high in beneficial fatty acids, especially the all-important omega-3. They are also rich in vitamins and antioxidants. One ounce of walnuts contains about 18 grams of fat. Walnuts are packed with nutrients that offer health benefits such as lowering cholesterol and improving mental functioning. Walnuts even contain melatonin, which is known to promote healthy sleep.
- Black Walnuts, native to Northeastern U.S. and Canada, are toxic to horses and dogs, but non-toxic to cats. Juglans regia, the common or English walnut, is native to Asia but is now grown around the world. They are toxic to horses and dogs, but non-toxic to cats.
- The walnut contains natural antioxidants that protect the oily nutmeat from the oxygen in the air. These antioxidants make walnuts especially nutritious. Like harvested fruits, walnuts continue to respire after they are picked. They continue to absorb oxygen and give off carbon dioxide. This means care is needed when storing and transporting large quantities of walnuts. They can lower available oxygen and raise carbon dioxide to dangerous levels.
- If you have a walnut tree in your neighborhood, know that dogs ingesting old walnuts off the ground have the potential to develop tremors and seizures from walnut hulls that are moldy and contain penitrem A.
So Can Dogs Eat Walnuts?
As you can see, one ounce of walnuts contains about 18 grams of fat. The average 12-pound puppy needs 21 grams of fat per day, while the average 33-pound adult dog needs 14 grams of fat per day. An ounce of walnuts could provide just about all the fat your dog needs each day.
In fact, fat naturally makes up a large amount of a canine’s diet.
One study found that when allowed control over their diet over a long period, dogs will choose to eat about 30% protein, 63% fat, and 7% carbohydrates.
In other words, dogs are naturally designed to get most of their nutrients from fat.
So, the fat in walnuts isn’t bad for dogs, and actually fits into their diet quite well.
However, this doesn’t necessarily mean dogs can eat walnuts or you should give your dog a walnut.
Walnuts Are Poisonous To Dogs
While the fat in walnuts isn’t bad for dogs, the fungi that grow on walnuts can be. Check carefully here:
- In one study, 100% of walnuts purchased from grocery stores were contaminated with different kinds of fungi.
- Walnuts can be infected with fungi at any stage, from harvest to the store shelf. They can be infected whether they are shelled or not.
- The problem is that walnuts have a high moisture content. They can be dried as part of processing them for eating, but that doesn’t eliminate fungal growth.
- Some fungi that grow on walnuts produce metabolites called mycotoxins. Certain fungi produce mycotoxins that are known or suspected to be carcinogenic.
- Others produce tremorgenic mycotoxins, which can cause tremors and seizures.
- The kinds of fungi that produce tremorgenic mycotoxins are also common in garbage cans and compost piles.
- Anything a dog eats out of a garbage can or compost pile—not just walnuts—may be contaminated with tremorgenic mycotoxins.
Symptoms Of Dogs Eating A Walnut
If your dog eats a moldy walnut, there are several symptoms you might start to see amongst other symptoms. Ingesting tremorgenic mycotoxins can cause:
- Muscle tremors
- Increased heart rates
- Body temperatures
- Lack of appetite
Studies of dogs with these symptoms have determined walnuts were the cause when their shells or remnants were found in the dog’s vomit.A lot of people whose dogs ate moldy walnuts did not realize their dogs had consumed them until the symptoms were visible.
So what should you do if you notice these symptoms?
If you’ve seen your dog eat fresh walnuts, or suspect they have, you should call your vet.
If Dogs Eat Walnuts What Should You Do?
There are two types of walnuts that dogs can be eaten: fresh walnuts and moldy walnuts.
- Fresh walnuts shouldn’t contain tremorgenic mycotoxins, consuming a small amount of fresh walnuts shouldn’t cause the symptoms listed above. However, even if your dog gorges on fresh walnuts, the high fat level can cause vomiting, so you should call your vet for advice on how to proceed.
- Moldy walnuts are so harmful. If you dog ingested and is experienced the symptoms listed above, the situation is more serious. If your dog has mycotoxin poisoning, it will need to be hospitalized and treated as soon as possible.
Your dog will most likely have its stomach pumped and given activated charcoal to absorb the toxins in your pup’s digestive system. If your dog is experiencing seizures, the treatment may be slightly different and could take slightly longer.
Walnuts Washed, Can Dogs Eat?
Walnuts washing can remove some of the mold you see on a walnut. But fungi don’t just sit on top of the nut; they have filaments that grow deep below the surface. So washing walnuts won’t remove all fungal growth. The mycotoxins that fungi create can’t be seen with the naked eye, so there’s no way to tell if they have been washed off.
Some recommend washing walnuts with vinegar. Others recommend boiling water, followed by thorough drying. There’s no guarantee this will be effective, though.
If you’re looking for foods that can increase the fat content in your dog’s diet, there are plenty of options you can choose from. Walnuts aren’t worth the risk they pose to our pups. Risking mycotoxin poisoning isn’t worth it for the benefits of the fats provided by walnuts. After all, your pet’s health should always be the first consideration when looking to introduce new foods.
You should also make sure your dog never eats moldy walnuts because your pet can become really sick and can require emergency treatment. There are tons of other foods your dog can eat to get healthy fats or if you’re looking for something you can share with your dog as a snack.
“Nuts in general have a high fat content, so even if they are not toxic, they can still cause an upset stomach in some dogs”, assured by Dr. Ashley Hughes, DVM, at Friendship Hospital for Animals in Washington, DC.
References for Further Reading:
- Boysen, S.R., et al., 2002, “Tremorgenic Mycotoxicosis in Four Dogs from a Single Household” Journal of the American Veterinary Medical Association, Vol. 221, Issue 10, pgs. 1441-1444
- Coleman, A.E. and Merola, V., 2016, “Clinical Signs Associated with Ingestion of Black Walnut Tree (Juglans Nigra) Wood, Nuts, and Hulls in Dogs”: 93 Cases (2001–2012), Journal of the American Veterinary Medical Association, Vol. 248, Issue 2, pgs. 195-200
- Elliot, P., 2018, “Do Dogs Need a Low Fat Diet?” Dogsnet
- National Academy of Sciences, 2006, “Your dog’s nutritional needs”.