What I Wish I’d Known About Acorn Poisoning in Dogs: Signs, Prevention & Treatment

acorn poisoning in dogs

Acorns are the nuts of the oak tree, and during Autumn and Winter, acorns can be found scattered around the woods and on your dog walks, so you are highly likely to come across them. Some dogs will find them interesting and give them a good sniff and then move on, others may pick them up and eat them.

Acorns are toxic to dogs if eaten, so make sure you keep an eye on your dog if they decide to investigate further. There is the possibility of obstruction, permanent liver and kidney damage and a very distressing time for your dog if they have scoffed an acorn.

My old Bull Mastiff, Keeper, was a terrible scavenger and he loved long rambling walks across the fields (until he’d had enough, then he used to sit down and refuse to budge). My dad had to come and retrieve us in his pickup truck on numerous occasions, but I digress.

We were out on a lovely late afternoon walk near the woods, enjoying the warm sunshine as the last rays of the day bathed the fields in autumn colours. Keeper disappeared into the hedgerow and came out chomping on something a minute later. As a few acorn cups fell from his jaws, I realised he’d just eaten acorns. I had no idea how many he may have wolfed down, but didn’t think anything more of it.

One evening a few days later, he started drooling more than usual, and as a mastiff, he drooled quite a bit! Then he wandered to his bowl and gulped down a gallon of water. After that, he was pretty lethargic, but I thought he was just tired out after his walk, so we all went to bed.

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The next morning he didn’t get out of bed. I knew something was wrong. I called the vet. We took him straight in for an examination and the vet said he suspected acorn poisoning. Keeper must have eaten a reasonable amount of them to make him poorly, so the vet gave him activated charcoal and some fluids to flush them through his system.

We kept an eye on him and he recovered fine, but a smaller dog, like our Pekingeses, might not have been so lucky.

Now, after my story, here’s what I learnt about acorn poisoning in dogs to share with you.

Are Acorns Poisonous To Dogs?

Acorns are poisonous to dogs as they contain a chemical called gallotannin which can cause stomach upsets and kidney failure and death in very severe cases. As they are hard and fairly large they can also cause obstructions in the intestines in small dogs if eaten. So be on your guard this autumn.

The technical term for acorn poisoning is “quercus poisoning“, which can also occur after a dog eats oak leaves.

What Are The Signs That Your Dog Has Eaten Acorns or Oak Leaves

Signs that your dog has eaten acorns or oak leaves include:

  • drooling
  • retching
  • vomiting
  • diarrhoea
  • lethargy
  • abdominal pain
  • collapse
  • excessive thirst

The severity of these symptoms will depend on the amount of acorns your dog has consumed and will start a few hours after ingestion. It’s a size to weight ratio, so a big dog eating one acorn would have milder signs than a small dog eating a lot of acorns.

Make sure no acorns or oak leaves have fallen into your dog’s bowl if it’s outside, as the gallic and tannic acids can leech into the water and make it poisonous. This also applies to puddles and other wild water sources that fallen acorns and oak leaves may contaminate.

Obstructions Are Your Biggest Concern

Acorns come in a variety of sizes, from small to large. They are typically round or oval in shape and include a hard, bumpy cap and rigid stem attached. Acorns have a smooth, glossy outside and are hard all the way through.

When wet, acorns become slippery, whether with rainwater or saliva. Whether a dog tries to gnaw on the acorn, it will be difficult to grip it with its teeth and instead may accidentally consume the nut whole.

Swallowing a whole acorn can cause choking. A large or even medium-sized acorn might get caught in a dog’s throat and prevent it from breathing which can be fatal.

Acorns can also cause an intestinal obstruction if consumed whole. They also have sharp points and stems that scratch or tear the stomach wall causing other complications.

How Long Does It Take Before I See Any Effects?

It depends how many your dog ate, but generally within 24-48 hours there should be some visible signs. If your dog had only just started eating acorns, you might not notice anything until 48 hours later when they start showing more obvious signs such as vomiting and diarrhoea. The longer your dog was exposed to the toxins the worse their condition will become. Sometimes symptoms can take a week to appear so if you notice a sudden change in your dog and suspect acorns, please contact your vet.

Contact your vet straight away if you think your dog has eaten an acorn.

Preventing Your Dog From Eating Acorns

The best way is to limit your dog’s exposure to temptation. Avoid areas with lots of oak trees during the autumn and winter. Keep them on a lead if you are walking through an acorn littered area. It is also good to make sure that you have ‘drop it’ and ‘leave it’ commands on cue so that if they do pick up an acorn, you can tell them to put it down.

Look out for these signs of acorn poisoning in your dog

Some indicators of poisoning due to your dog eating acorns can include:

  • drooling
  • retching
  • vomiting
  • diarrhoea
  • lethargy
  • abdominal pain
  • collapse
  • excessive thirst

What To Do If Your Dog Eats An Acorn

Don’t wait. Contact your vet immediately if you suspect they have eaten one and ensure your dog receives treatment as quickly as possible.

Will my dog be OK?

If your pet is treated immediately, the outlook for your beloved companion is good. About 75% of dogs will exhibit symptoms of poisoning, but severe symptoms are uncommon if you get prompt treatment. 

If massive amounts of acorn have been consumed and your dog isn’t treated promptly, the outcome might be more unpredictable so contact your vet straight away. 

Dog Acorn Poisoning FAQs

How do I stop my dog from eating acorns?

Keep a close eye on your dog to make sure they are not picking up an acorn or conker. Don’t encourage your dog to play catch or fetch acorns. Change your walks to avoid areas that are likely to be littered with acorns.

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

Your dog may need to be rehydrated and given medications to manage their symptoms depending on the severity. In the case of an acorn causing a blockage, an x-ray will be performed and surgery will be needed to remove the blockage.

My dog ate an acorn, what should I do?

Contact your vet as soon as possible. Acorn toxicity should be treated promptly. Do not try to make your dog sick, as it may not be necessary and can be harmful to your pet in some circumstances. 

How many acorns make a dog sick?

If a dog consumes 6% of its body weight in acorns, it is at risk of gallotannin poisoning.

Are Acorn Caps And Oak Leaves Poisonous To Dogs?

The bark, roots, leaves, and acorn buds and caps are all poisonous to dogs in large quantities. Gallotannin is found in all parts of the oak tree.

Are conkers dangerous for my dog?

The horse chestnut tree is poisonous to dogs due to the presence of a chemical known as aesculin. This substance may be found in all portions of the horse chestnut tree, including its leaves. Second, your dog’s stomach might become blocked by the huge conkers.

 Can acorns cause seizures in dogs?

Excessive consumption of acorns, including poison, toxins, and kidney disease, might all cause seizures in dogs.

Are oak trees toxic to dogs?

Oak trees and oak acorns and oak leaves are toxic to dogs. Oak poisoning in dogs can result in severe gastrointestinal distress, including vomiting, lethargy, diarrhoea, nausea.

Are acorn caps poisonous?

Acorn caps are not poisonous, but the acorns they cover are. Acorn caps if consumed are more likely to damage the walls of the intestine due to their rough texture and spiky stem.

Why are tannins toxic to dogs?

Tannins can bind with substances like proteins and enzymes in animal digestive systems, which reduces their ability to function properly. The absorption of tannin-containing foods also interacts with certain medications or other nutrients in an animal’s system (such as iron for humans). Tannins may slow the production of red blood cells (erythrocytes), which help carry oxygen through your body; reducing erythrocyte production means less oxygen is carried through your system, possibly causing weakness or breathing difficulties.

What part of the acorn is toxic to dogs?

The acorn nut itself is toxic as well as the oak leaves from the tree. Both have the potential to cause severe problems to your dog.

Why does my dog eat sticks and acorns?

Reasons your dog is eating sticks and acorns include: boredom, anxiety, nutritional deficiencies, and medical conditions.

How do you treat acorn poisoning in dogs?

Your vet will recommend the treatment appropriate for your dog. Generally this includes: activated charcoal, intravenous fluids, x-rays to find blockages and occasionally surgery.

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Acorns are poisonous to dogs

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