Are conkers poisonous to dogs?

Conkers come from the horse chestnut tree and fall to the ground during autumn in the UK. These trees are common along streets and in parks too. Research indicates that there are almost half a million horse chestnut trees in Great Britain. 
conkers poisonous to dogs

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Luckily, conker poisonings are not common in the UK, and if treated quickly, the prognosis is generally good. Contact a vet immediately if you suspect your dog has eaten any conkers.

Are conkers bad for dogs? What are the dangers?

Yes, conkers pose several different threats to dogs. You should always contact your vet immediately if your dog has eaten any conkers. Life-threatening episodes are rare, but conkers can cause serious problems. 

are conkers poisonous to dogs

Obstruction and choking

Because of their shape and size, when ingested, conkers can cause an obstruction or blockage in the stomach or intestine. They can also cause dogs to choke. These are both extremely serious conditions that require immediate attention and complex surgery. 


Secondly, conkers contain a substance called aesculin. This substance is toxic to dogs. Poisoning can range from mild to severe symptoms, usually depending on how many have been eaten. 

How poisonous are conkers?

Conkers can cause severe disease in dogs, especially if more than one is eaten or if your dog is small. Conker poisoning has been known to be fatal in dogs, though this is thankfully quite rare. 

How many conkers does a dog need to eat to make them ill?

Unfortunately, it is impossible to say how many conkers are poisonous to dogs, as they all contain different amounts of the toxin. 

conkers bad for dogs

What are the symptoms of conker poisoning in dogs?

Symptoms of conker poisoning in dogs can vary from mild to more serious, and this usually depends on the quantity eaten. 

Mild symptoms include 

More serious symptoms include

  • Tummy pain
  • Collapse
  • Tremors
  • Wobbliness
  • Shock and breathing problems 
symptoms of conker poisoning dogs

What happens if my dog chews a conker?

Symptoms of conker poisoning usually start within 1 to 6 hours after ingestion. But signs may also be delayed by up to a few days. 

Treatment of conker poisoning depends on how severe the symptoms are and how quickly your dog is seen after ingestion. 

  • If caught quickly, your vet might make your dog vomit to bring up the conkers before the toxin takes full effect. 
  • Mild cases might be treated at home with anti-sickness and other supportive medication. 
  • More severe cases usually require hospitalisation for fluids and monitoring. They may also need a gastric lavage, which is where the stomach is emptied to remove as much toxin as possible. 
  • Obstructions and blockages require complex surgery. 

What should I do if I think my dog has eaten a conker?

If you suspect your dog has eaten a conker, we recommend contacting your vet straight away, even if your dog is not showing any signs of illness. Waiting to see if any symptoms develop can lead to a longer recovery or a poorer prognosis.  

Make a note of the time and how many were eaten. Remove your dog from the area where the conkers are immediately. 

Your vet might advise you to call the animal poison line

How do I stop my dog eating conkers?

Try to be aware of what the horse chestnut tree looks like, and avoid areas with this tree in the autumn if possible. 

  • Keep your dog on a lead in high risk areas if they are prone to eating things they shouldn’t.
  • You can use a basket muzzle if your dog is prone to scavenging objects on the ground. 
  • If you have this type of tree in your garden, make sure to remove any fallen conkers in the autumn period and keep your dog out of the garden until it is safe. 
  • If you see your dog eating a conker, try to remove it from their mouth if it is safe to do so. 
  • Take a toy or treat on walks to distract your dog with in high risk areas

What other parts of the horse chestnut tree are poisonous to dogs?

All parts of the horse chestnut tree contain the toxin aesculin, even the bark, flowers, and leaves. 

chestnut tree

Our Joii vet team are available 24 hours a day for advice.

Read more about different autumn dangers for your pet

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