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Are Acorns Bad For Dogs?

Dog sniffing tree in fall
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Sometimes, you may hardly notice you have acorn-producing trees in your neighborhood. But every two to five years—during what’s called “mast” years—oak trees release abundant showers of acorns in the fall (1). When they ping-pong off your roof, scatter across your backyard, and stain your driveway and sidewalks, you know it’s acorn season. With so many interesting new treats around, some dogs might try to eat them. 

If you’ve been triggered by that classic dog-got-into-something crunch, you’re probably wondering if a dog eating acorns is something to worry about. As it turns out, these tree nuts are not a safe snack for dogs. In some cases, they can even cause serious health complications. That’s why if there’s any indication your dog has been eating acorns, you should listen to your gut and call your veterinarian ASAP to figure out next steps. 

Read on to find out whether acorns are bad for dogs, what to do if your dog eats acorns, and how to prevent this risky behavior. 

Are Acorns Bad for Dogs? 

Closeup of acorns in tree

A common feature of fall decor, acorns look pretty harmless. But these bitter-tasting tree nuts can be bad for our canine companions. “Some dogs can have gastrointestinal upset from eating acorns like vomiting, diarrhea, or an upset stomach,” says Dr. Erin Ray, a clinical assistant professor of primary care and general surgery at Texas A&M University Veterinary Medical Teaching Hospital (2). 

Are Acorns Poisonous to Dogs? 

Acorns don’t just turn your dog’s stomach. You might be surprised to learn that acorns can also make dogs dangerously sick.

Interestingly, acorns are especially toxic to cattle and horses. This is likely due to high amounts of harmful compounds called tannins, which are made of tiny bits of poisonous particles (3). Fortunately tannins are very bitter, which makes most dogs think twice about taking a second bite.

While there have been more reports of serious complications in larger animals, research suggests toxic compounds found in acorns seem to impact dogs in similar ways. As such, no matter the size of your pup, it’s best to keep acorns off the menu. 

Mature acorns—the brown ones that fall from trees—contain toxins that are bad for dogs. But buds and immature green acorns actually contain the highest concentration of toxins. So be sure to keep acorns of all types away from your pup throughout the year. 

4 Dangers of Acorns for Dogs 

Dog running in autumn leaves

While plenty of dogs aren’t interested in munching on acorns, it’s worth knowing what may happen if your dog eats some and what to do. 

Keep in mind that there are very few reports of dogs who get sick from acorns, despite how widespread acorns are and how many dogs have access to them.

Here are a few potential health hazards to know: 

1. Acorn poisoning 

Within hours, toxins found in acorns can disrupt your dog’s ability to digest food as they’re released inside the GI tract. Over time, they can also cause serious damage to organs like the kidneys and liver (3).

Although this does not happen often, there have been a handful of reports of sick dogs showing up at the veterinarian’s office with a belly full of acorns. In one case, a pesky Labrador allowed to run free in his parents’ yard gobbled up around 10 to 15 acorns. He later became lethargic and eventually suffered from a bout of vomiting and diarrhea. Thankfully, with supportive treatment from a veterinarian, he was able to get out of the danger zone and recover (3).

While extreme, this is one clear example of why pet parents shouldn’t ignore acorn-related health problems. “If you’re concerned a dog has eaten acorns, you need to go to the veterinarian,” says Dr. Nancy Welborn, an assistant professor of veterinary clinical sciences at the LSU School of Veterinary Medicine in Baton Rouge. 

With next steps like a physical exam, abdominal palpation, bloodwork, and imaging, your veterinarian can determine the best course of action to protect your pet. 

2. Gastrointestinal blockage 

One of the most common reasons veterinarians see dogs for acorns is obstruction. Acorns can get stuck in part of the GI tract, such as the small intestine, and block it up. Depending on how recently the acorns were eaten and the size of the dog, veterinarians can palpate or feel around the belly for the presence of acorns. If the dog ate the acorns within the past few hours and they are still in the stomach, your veterinarian may be able to induce vomiting to get rid of them or go in with an endoscopy (a tool to see inside the body) to remove them, says Dr. Welborn.  

3. Choking hazard 

In general, it’s clear that you don’t want your dog eating acorns. But if yours is gobbling them up, there’s also the potential danger that they could choke on pieces of acorn or a whole nut, Dr. Ray says.   

Rough pieces of acorns can be irritating to the esophagus even if they don’t cause choking. This can lead to pain, decreased appetite, and even hacking up small amounts of blood.

4. Dental damage 

Another worry: “Acorns can cause dental trauma if they’re hard enough when chewed on,” says Dr. Ray. Very hard objects from nuts to chew toys can break a dog’s teeth. If left untreated, tooth fractures can cause a lot of pain and open the mouth up to a potential infection (4).

The good news is, many dogs aren’t interested in eating acorns anyway. But if yours is on the curious side or tends to gobble down just about anything when he’s hungry, there are ways to keep him from getting into acorns or manage an exposure. 

What to Do If Your Dog Eats an Acorn 

Man pulling object out of dog's mouth

If you catch your dog with an acorn, step one is to stop him from eating it. “It would be best to try to gently remove the acorn from your dog’s mouth if you’re able to do so safely,” says Dr. Ray. 

Often, it’s tempting to just watch and wait if your dog gets into something you suspect might not be good for him. When it comes to acorns, though, put your dog’s health and well-being first. Dr. Welborn recommends reaching out to your veterinarian for their advice no matter what. 

“We always err on the side of safety because there’s really no known dose per dog, so it depends on the dog, what they’ve eaten, and the amount they’ve eaten,” she says. For these reasons, at the very least you want to call your veterinarian to talk it out. 

Early signs to look out for that could indicate acorn poisoning in dogs include a dip in energy, loss of appetite, vomiting, and diarrhea (3).

How to Prevent Dogs from Eating Acorns 

Girl walking dog on path in fall

Clearly, prevention is the best medicine when it comes to dogs and acorns. To keep your dog from eating acorns, follow these tips:

Brush up on basic training cues. If your dog seems to have no interest in eating acorns, it’s okay to let him be around them. But if he goes for them, start training him with “leave it” or “drop it” commands to teach that acorns are always off-limits. 

Rake up acorns. Clearing your yard of acorns can be a major headache. But if your dog has a penchant for eating acorns and you haven’t been able to train him out of the habit, it’s your best bet to keep him safe—especially if he’s an outdoorsy boy. 

Take leashed walks. If removing acorns is too tall an order, that’s perfectly understandable. In some places, an acorn-free yard is all but impossible. In this case, try to stick with leashed walks and be on acorn alert as you go. 


  1. “Why Are There So Many Acorns This Year?” Purdue University Forestry & Natural Resources. Oct. 2021. Retrieved from https://www.purdue.edu/fnr/extension/question-why-are-there-so-many-acorns-this-year/
  2. Autumn poisoning hazards for pets. The Veterinary Nurse. Sept. 2022. Vol. 13, No. 7. https://doi.org/10.12968/vetn.2022.13.7.318
  3. Camacho F, Stewart S, Tinson E. Successful management of suspected acorn (Quercus petraea) toxicity in a dog. Can Vet J. 2021;62(6):581-585.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8118173/
  4. Risks from a fractured tooth. Cornell University College of Veterinary Medicine. Retrieved from https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/health-info/risks-fractured-tooth