Can Dogs Eat Acorns? Or Are Acorns Bad For Dogs?

Ask any number of people around you about what their favorite season is, and a large portion of them will answer “Fall.” People love the pleasant daytime temperatures, the slight chill in the evenings, and the natural beauty of the leaves changing colors.

Accordingly, it makes plenty of sense that many dog owners find this time of year to be the best time to take their four-legged family members out for long, brisk walks as well. After all, it’s the rare time of year where both dog and human can enjoy the beautiful climate and scenery, without the worries of things like springtime allergies, summertime heat, and wintertime cold.

However, there is one thing you and your dog need to watch out for during this beautiful time of year: the acorns that have fallen off trees.

Can Dogs Eat Acorns? Or Are Acorns Bad & Poisonous For Dogs?

Most acorns mature in late summer, and begin falling off trees in September and October.

While you might think of acorns as simply being another nut, and thus being okay for dogs to consume, it’s actually the complete opposite. So, the short answer to this question is: NO, dogs can’t safely eat acorns and acorns are bad & poisonous for dogs to eat.

There are a handful of issues that could arise if your dog happens to eat an acorn, and some of them could be very dire.

Why Are Acorns Bad For Dogs To Eat?

At a basic level, acorns are the nut of the oak tree, and thus often referred to as “oak nuts.” 

According to the website of the American Society for the Prevention of Cruelty to Animals® (ASPCA) website, the oak plant is listed as being toxic to horses, though there is no specific mention of it being toxic to dogs.

In fact, if you search the organization’s website for plants toxic to dogs, the oak tree does not come up in the search results.

That being said, the ASPCA does warn that “the consumption of any plant material may cause vomiting and gastrointestinal upset for dogs and cats.” 

So when it comes to acorns, your dog isn’t necessarily out of the woods, so to speak (yes, pun intended).

In fact, when it comes to acorns, there are two basic things you need to understand and keep in mind at all times:

Gallotanins 

The reason why oak plants — and acorns, by extension — are potentially harmful to dogs is because of Gallotanins.

Without turning this into a biology lecture, Gallotanins are chemical compounds that belong to a larger class of chemicals called tannins.

Tannins are commonly found in a wide variety of plants, seeds, nuts, and fruits, and are often considered to be powerful antioxidants. 

While we usually think of antioxidants as being good for us, while a little of something might be good, too much of it isn’t better. The levels of gallotanins in acorns is so high and so concentrated that it can actually have toxic effects on dogs, among the other domestic animals mentioned. 

The gallotanin within acorns is mostly concentrated within its hard outer shell, so if a dog decides to bite or chew the acorn, they’ll be directly releasing the gallotanin into their mouth, and consequently into their digestive system.

Digestion

This one is a bit more obvious.

We all know that dogs tend to swallow as much food as they chew, so if they happen to swallow an acorn, you can imagine that this could be a problem.

Just as how you don’t want a young child to swallow something large that could potentially obstruct their airway, you don’t want your dog to consume something that’s going to cause them gastrointestinal — aka digestive — issues.

When a larger dog consumes an acorn, it isn’t broken down by their body. Many times, it just sits there in their stomach.

While that might not seem like an issue, just imagine if you had something sitting there in your stomach that couldn’t be properly digested; that could lead to a whole host of other issues down the road.

Plus, in the case of small dogs, it only makes sense that the issues could be much worse, as an acorn is large enough to cause serious blockage and harm in their smaller digestive tracts.

Serious Side Effects Of Acorn Consumption In Dogs

Obviously, neither of the two items mentioned above sound particularly pleasant, and they could lead to a handful of serious issues for your dog. The following are the three most often associated side effects observed in dogs that consume acorns.

Gastritis

One of the most common issues that dogs face if they consume one too many acorns, and the toxins from the acorns get into their system, is gastritis.

Simply put, this is when their stomach becomes irritated or inflamed because their system is trying to break down and digest something that, essentially, they’re not supposed to eat.

As a result, they’ll exhibit many of the same symptoms that us humans have when we’re dealing with a nasty case of food poisoning: abdominal pains, excessive vomiting, loose stool, dehydration, excessive thirst, blood in the vomit or stool, and lethargy.

Gastrointestinal Obstruction

This one goes back to the idea of acorns essentially being “indigestible” for dogs. If they’re just sitting there inside your dog’s system, they’re bound to cause digestive and intestinal blockages.

That will immediately affect your dog’s ability to break down the food he or she eats, and properly “process” it, since the blockage could prevent the nutrients and the waste products going to the right places.

In addition, there’s the possibility of an imbalance of hydrochloric acid in the digestive acids produced by a dog’s stomach, given the foreign object stuck in its systems, which will further inflame your dog’s stomach lining. 

According to PetMD, the visible symptoms of Gastrointestinal Obstruction include vomiting (especially after eating), sudden & dramatic weight loss, diarrhea, dehydration, and weakness.

Kidney Failure

Going back to the Gallotannin issue, the increased presence of this chemical in your dog’s system may have very harmful effects on their kidneys.

However, this is very rare and often caused by the consumption of an abnormally large amount of acorns.

Renal failure (the official term for Kidney failure) is more often the case for sheep and cattle, who tend to consume very large quantities of acorns while grazing in fields.

With that being said, you do have to keep in mind that if your dog is particularly sensitive to acorns, or ends up consuming a lot more than they should, this is a possibility, albeit a long shot. 

Kidney failure usually comes with the same combination of symptoms mentioned above for Gastritis and Gastrointestinal obstructions, but could also include much more severe issues such as seizures, coma, and acute (temporary) blindness.

My Dog Ate An Acorn, What Do I Do?

To be clear: we’re not trying to scare you in regards to dogs and acorns. We’d rather present you with the potential worst case scenario information, so that you’re fully informed.

But in complete honesty: dogs are just like humans. They all have varying degrees of sensitivity to different foods. 

If you took a random sample of 100 different people, you’ll almost certainly find people who have trouble digesting things like gluten, eggs, dairy, shellfish, among numerous other types of foods, while others in that same group will have no trouble if they consume any of those. 

If some of those people consume foods that are slightly under-cooked or slightly rotten, they might exhibit “food poisoning”  symptoms and quickly expel the contaminated foods from their system.

But other people might have far worse symptoms that require a much more substantial level of treatment.

The same thing is true for dogs, especially in the case of acorns. Some dogs might not like acorns, as they find the bitter taste doesn’t suit them. Some dogs, on the other hand, might not have an issue with the taste.

If you scour internet message boards frequented by pet owners, you’ll find numerous stories of owners who say that their dog has grazed on acorns in the backyard for as long as they’ve had the dog, with virtually no issues.

However, others will tell you that their dog consumed a very small volume of acorns, leading to a whole series of stressful, painful, and costly visits to the vet.

Better Safe Than Sorry!

As the saying goes: “what’s good for the goose isn’t always good for the gander.”

Ultimately, it’s our recommendation that you’d be better off shying away from allowing your dog to eat acorns, without having to wonder what will happen to them if they do consume one.

Taking the chance of something bad happening to your dog if you let them consume acorns to their heart’s desire is simply not worth it, given the potential outcomes that could arise. 

You’d rather be a parent of a safe canine, versus the parent of a sick canine.

To that end, here are a few tips we have for doing your best to ensure you and your dog don’t find yourself in this situation.

Yard Maintenance: If you have a tree in your backyard that tends to grow acorns, do your best to keep your yard free of any that may have fallen off the tree. They’re fairly easy to rake up, accumulate, and scoop out into a garbage bag.

Distraction Items: Keep things like your dog’s favorite toy or tiny treats handy, to distract them from potentially consuming acorns.

Verbal Commands: Reinforce any obedience behaviors you may have trained your dog(s) with, so that if you happen to notice them reaching down to consume something that could potentially be harmful to them, you can stop them from doing so.

Of course, no method is perfect. Sometimes your dog won’t know better, and sometimes you simply won’t be there to catch them before it happens.

If you witness your dog consuming an acorn, make sure you keep a close eye on them for the next few days (if not longer) and monitor for any abnormal symptoms that may arise. 

If you notice any of the symptoms we outlined above, be sure to take your dog to the veterinarian’s office, and make sure to tell the vet that you suspect (or know for a fact) they consumed an acorn. Your veterinarian will tell you what steps need to be taken from there on.