Are acorns and conkers poisonous to dogs?

The short answer

Yes, both acorns and conkers are poisonous to dogs. Not only are they a choking risk, acorns contain tannins and conkers contain aesculin - both of which can make dogs unwell. If your dog ate acorns or a conker, don’t panic. Serious illness is rare, but you should still call your vet straight away for advice.

Why acorns and conkers are worth watching out for

Acorns and conkers dropping from the trees is a sure sign autumn has arrived. While you might see squirrels munching on these nuts and seeds, they aren’t safe for dogs to eat. 

Luckily, keeping your pup safe on an autumn walk is as simple as making sure they don't pick up and chow down any acorns or conkers on the ground.

If you want to treat your pet to a seasonal snack, steer clear of anything found under the trees. It’s best to check with your vet first in case of any allergies, but generally, blackberries make a natural snack that’s safe for dogs to eat and can be baked into tasty treats!

Can dogs eat acorns?

No, dogs shouldn’t eat acorns. Whether the acorn is green or brown, picked off the tree, or eaten off the ground, it shouldn't be going in your dog's mouth.

If your dog eats an acorn, they’ll usually suffer from a gastrointestinal illness like vomiting or diarrhoea. It's very rarely life-threatening, but if your dog eats a large amount it can lead to kidney and liver disease, so prevention is better than the cure.

Acorns are also a choking hazard and eating them can cause an intestinal blockage (especially in much smaller and younger dogs). Keep your dog away from acorns, or get them to drop any they pick up.

Are acorns poisonous to dogs?

Yes, acorns are considered poisonous to dogs. All parts of an oak tree are toxic to dogs, whether it's the bark, roots, leaves, or acorns. This is because the oak tree, and its acorns, contain a natural chemical called tannins which are toxic to dogs.

Like many things, the risks of toxicity are higher if you have a smaller dog. A tiny breed like a Chihuahua is at greater risk of illness after eating acorns compared to a bigger breed like a Labrador. This is simply because smaller bodies have a lower tolerance to toxins.

However, it's pretty rare for dogs to suffer from poisoning after eating acorns. The more common risks are choking or intestinal obstruction. Smaller dogs are at greater risk of these problems too, since their oesophagus and digestive tract are all smaller.

Are conkers poisonous to dogs?

Yes, conkers are poisonous to dogs. Conkers are the seeds of the horse chestnut tree, and every part of the tree, including the conkers, their spiky casings, the leaves, and the bark contains a chemical called aesculin, which is toxic to dogs.

If your dog eats a conker, they might suffer from vomiting, diarrhoea, drooling, and abdominal pain. Signs usually appear within a few hours, but they can sometimes take a day or two to show. In more severe cases, dogs can become wobbly, restless, or develop muscle tremors, though serious poisoning is rare.

As conkers are bigger and harder than acorns, they're an even greater choking and blockage risk. A single conker can block a dog's gut, especially in small and medium breeds, and a blockage may need surgery to remove. This makes conkers a hazard for dogs of every size, not just toxic in large amounts.

What's the difference between conkers and sweet chestnuts?

Conkers come from horse chestnut trees and are toxic to dogs. Sweet chestnuts, the kind roasted and eaten by people, come from a different tree entirely and aren't poisonous in the same way.

You can tell them apart by their casings. Conkers sit in a thick green shell with short, spaced-out spikes, while sweet chestnuts have a much finer, densely bristled husk, a bit like a hedgehog. Even so, it's best to stop your dog eating either, as whole nuts of any kind are a choking and blockage risk.

What should I do if my dog has eaten acorns or conkers?

If your dog has eaten acorns or a conker, don’t panic. Although they can make dogs sick, their life isn't usually in danger. So focus on trying to stop your dog from eating what they picked up, and prevent them from eating any more.

If your dog knows a cue like "leave" or "drop", use it. Hopefully they'll spit the acorns back out. As long as your dog is happy to have their face handled, you can open their mouth and try to get them to drop what they’re holding. You should also get your dog on their leash and lead them away from the area where the acorns or conkers have fallen.

Whatever you do, don't try to make your dog vomit. You're more likely to make your dog sicker if you do. Instead, call your vet for advice. They'll let you know whether your pup needs to come in for treatment. As conkers are large enough to cause a blockage, it's especially important to speak to your vet if you know one has been swallowed whole.

How can I stop my dog from eating acorns and conkers?

Keeping your dog safe is as simple as stopping them from eating acorns and conkers. As the old saying goes, prevention is better than the cure!

Keep them on the lead

This might mean keeping them on their lead when you walk under oak or horse chestnut trees where acorns and conkers have fallen and gathered, or steering them away from anything they shouldn't be eating.

Consider muzzle training

If you want to let your dog off lead, but they have a habit of eating things they shouldn't, it can be worth muzzle training them. 

A well-fitted muzzle won't hurt your dog, and they can still eat treats, drink, and breathe normally. It will effectively stop them from picking anything up they shouldn't, preventing the risk of choking, potential poisoning, or sickness.

Teach them to "leave"

You can also train your dog to understand a "leave" or "drop" cue. This takes time, but means you'll have another method of keeping your dog safe. It can work especially well if you train your dog to "swap" what's in their mouth for something better in your hand, like a treat or a toy.

If you’re struggling, an accredited dog trainer can help you train your dog obedience skills like a "leave" cue.

What happens if my dog eats acorns or conkers?

Eating acorns or conkers will usually cause stomach pain and digestive upset, such as:

• Retching

• Vomiting

• Diarrhoea

• Excessive drooling

• Abdominal pain

• Loss of appetite

• Lethargy

These symptoms usually appear within a few hours, though signs of conker poisoning can occasionally take up to two days to show. As long as you contact your vet promptly and follow their advice, it's highly unlikely your dog will suffer from any serious illness.

The more your dog manages to eat, the more severe their symptoms. In rare cases, dogs can suffer from intestinal blockage or toxicity. Acorn toxins can cause damage to the liver and kidneys if left untreated, while a swallowed conker is one of the more common causes of gut blockages in dogs during autumn.

If you're ever worried about your dog, contact your vet for advice.

Treatment for when a dog eats acorns or conkers

How your dog is treated after eating acorns or conkers will depend on how much they've eaten, when they were eaten, and your pup's size.

Most treatments given will help ease your dog's symptoms. This will probably include a brief stay in the vets to be observed. They'll also be given IV fluids to prevent dehydration and help the liver to remove any toxins from their body.

Depending on your dog's symptoms, they may be given an X-ray to check they don't have an intestinal blockage. Blockages are more likely with conkers because of their size, and if your vet finds one, your dog may need surgery to remove it. 

Vet treatment for a blockage can be one of the more costly emergencies a dog owner faces, which is where insurance can help. Napo pet insurance provides lifetime cover for dogs and cats worth up to £16,000 per year, helping you cover unexpected costs in a medical emergency and focus on taking good care of your dog.

Main takeaway

Acorns and conkers are both poisonous to dogs, so you should try to stop your dog from eating them. Choking or intestinal blockages are an even bigger risk than poisoning, especially with conkers due to their size. Again, preventing any problems is as simple as stopping your dog eating them.

Keep an eye on them on walks and use a "leave" command if they know it. Otherwise, keeping your dog on a lead or using a muzzle can help stop them picking up acorns and conkers. If your dog does swallow something they shouldn’t, contact your vet for advice.