Poppy enjoying a walk through woodland

Are acorns poisonous to dogs?

Along with leaves, autumn is the time of year when acorns and conkers are found on the ground. Sadly, some dog owners don't realise that these nuts can pose a serious health risk to your pet if eaten.

Acorns, like conkers, are poisonous to dogs if eaten. They can cause an upset tummy, and because they are hard and sometimes spikey, they can cause damage or a blockage in the stomach. In rare cases it has led to liver and kidney failure, so it’s important to be aware of your surroundings when walking your dog.

Although serious cases are rare, you should contact your vet straight away if you think your dog has eaten an acorn.

Acorns hanging on an oak tree

What are the symptoms of acorn poisoning in dogs?

Although fatalities are rare, if your dog has eaten acorns, it could still pose a serious threat. In general, the more acorns eaten, the sicker your dog may be.

Dogs who have eaten acorns can experience:

  • vomiting
  • diarrhoea
  • abdominal pain
  • loss of appetite 
  • dehydration
  • collapse
  • death (very rare)

If your dog has eaten acorns, signs of illness usually develop within a few hours.

What should I do if I think my dog has eaten an acorn?

Contact your vet straight away for advice. 

Why are acorns dangerous to dogs?

Acorns contain tannins, a type of chemical that is toxic to dogs. If eaten, acorns can cause upset tummies and, though rare, they can lead to liver and kidney failure and be fatal.

It is also possible for them to cause a blockage of the intestines in smaller dogs.

What treatment is my dog likely to receive if they have eaten an acorn?

Treatment for acorn poisoning will depend on how severe your dog’s symptoms are. Your vet might need to give medication to help with vomiting, diarrhoea and pain, or, in more serious cases, rehydration and blood tests may be required.

If your vet thinks the acorn might be causing a blockage in your dog's stomach, x-rays or surgery could be needed.

Are all parts of an oak tree poisonous to dogs?

Yes, all parts of an oak trees are poisonous to dogs, as the bark, leaves, wood and the acorns themselves all include tannins.

How do I stop my dog from eating acorns?

Dogs love snuffling through the autumn leaves with lots of scents to discover, so it's best to keep a close eye on them to make sure they’re not picking up anything dangerous – after all, prevention is better than cure! 

Some things you can do to prevent your dog from eating acorns include:

  • not encouraging your dog to catch or play with acorns
  • taking one of their toys on walks to play with as a distraction
  • teaching your dog commands such as ‘drop’ or ‘leave’ in the event of your dog picking up an acorn 
  • if you think it’s safe to do so and your dog is familiar with having things taken out of their mouth, you can try removing the acorn from your dog’s mouth if they’re already in the process of chewing one, or offering a treat as a distraction 

If your dog shows any signs of being unwell after your walk, call your vet immediately.

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• 23 November 2022

Next review

• 23 November 2025

Approved by
Róisín Bolger

Veterinary Surgeon MRCVS