Are Acorns Bad for Dogs?

We assume you’re here because your dog slurped up an acorn on a nice fall walk and you’re now wondering, “Are acorns bad for dogs?” Yes, acorns are bad for dogs. They usually aren’t lethal but ingesting them could cause major health issues if no action is taken. The sooner you contact your vet, the better things will be for your pup.

Acorns are the giant seeds of oak trees. To woodland critters like squirrels, mice and birds, acorns are hearty sources of protein. Deer love them! Unfortunately, other mammals, like canines and horses, are unable to effectively break down the tannins in acorns. Yep, like a fine wine, acorns contain tannins. Tannins are polyphenols, chemical compounds that are “bitter and astringent,” according to wine publication Decanter.

If you’re not sure your dog ate that acorn he was carrying around in his mouth, Vets Now recommends watching for diarrhea, vomiting or lethargic behavior. These symptoms usually show up around an hour after a dog has ingested an acorn. Other indicators are excessive drooling or stomach cramping, which could accompany some whining or yowling.

Banfield Pet Hospital also notes the shape of an acorn and its pointy shell can damage a dog’s throat or cause a painful abdominal obstruction. This could negatively impact swallowing and digesting other foods and liquids. Look for a loss of appetite or difficulty eating.

When a dog’s body tries to break down acorn tannins, the result is an acid that can do some serious damage to the kidneys or liver. In severe cases, these organs can shut down completely—a fatal result we want to avoid at all costs. Eating oak leaves could lead to the same issues (this is called Quercus poisoning).

The good news from the ASPCA is your pup would have to scarf down a whole bunch of acorns to reach lethal or lasting damage levels. However, acorns and oak leaves can do more harm, more quickly, to small dogs or animals with preexisting health issues. The bottom line? Keep your pups away from acorns!

First and foremost, avoid acorns as best you can. Don’t decorate your home with real acorns. Fancy cornucopias in autumn are pretty—we get it! But it’s just not worth it to include items that could harm your pet. Outdoors, stay away from large oak trees whenever possible, as they’ll probably be surrounded by hundreds of fallen acorns.

Second, train your dog as early as possible to spit out whatever’s in his mouth as soon as you say, “Drop it!” This command serves many purposes, not the least of which is training your dog not to eat everything he sees.

Finally, keep outdoor food and water bowls away from oak trees. Jon Gellar, DVM, writes on Chewy that if acorns or oak leaves fall into a pet’s water bowl, their toxins could contaminate the water and make your dog ill.

If you think your dog has eaten an acorn, oak leaf or a combination of the two, contact your vet immediately.