In autumn, parks, paths and oak woodland fill up with acorns. Lots of dogs love them: they roll, they crunch and they smell of the countryside. If you're asking yourself "my dog eats acorns – is it serious?", the short answer is that it's best to stop them. Acorns and the leaves of oak and holm oak trees contain tannins, which irritate a dog's stomach and gut and, in larger amounts, can damage their kidneys. Here's why they're toxic, which symptoms to watch for, what to do if your dog has eaten some and how to stop them doing it on walks.
Why are acorns poisonous to dogs?
Acorns, their cups (the little "hat") and oak and holm oak leaves contain tannins. These substances irritate the digestive system and, in larger amounts, can damage the kidneys and liver. Green acorns, the ones that fall before they ripen, contain more tannins than ripe ones. No safe amount is known, and how serious it is depends on, among other things, the dog's weight and how many they eat. Small dogs and puppies are affected sooner.
There's also a physical risk: a whole acorn can get stuck in the throat, and pieces of shell can irritate the intestines or even block them, especially in small dogs.
Dog eating acorns: symptoms to watch for
If your dog has eaten acorns, keep a close eye on them over the following hours and days. These are the possible symptoms:
- vomiting, sometimes repeatedly;
- diarrhoea, sometimes with blood;
- abdominal pain: they arch their back or don't want to lie down;
- loss of appetite and lethargy;
- drinking and urinating a lot or, on the contrary, hardly urinating at all.
Not every dog gets ill from an acorn, but you can't know in advance how yours will react. That's why any symptom should be taken seriously.
What to do if your dog has eaten acorns
- Take out anything still in their mouth and move them away from any acorns left on the ground.
- Work out how many they've eaten and when. Were they green or brown? Take an acorn with you or take a photo of one.
- Call your vet, especially if it's a puppy or a small dog, if they've eaten more than a few or if they already have symptoms. Out of hours, go to an emergency vet.
- Don't make them sick yourself with salt, soap or hydrogen peroxide: it can do more harm than good. Only the vet decides whether it's advisable.
- Keep an eye on them: make sure they have fresh water to hand and note down any symptoms.
Conkers and mushrooms: also watch out on autumn walks
Acorns aren't the only thing your dog comes across outdoors at this time of year:
- Conkers: they contain aesculin and can cause vomiting, diarrhoea and abdominal pain. They're also big and hard, so your dog could choke or suffer an intestinal blockage. You'll find all the details in our article on whether conkers are poisonous to dogs.
- Mushrooms: they're popping up everywhere right now. Some species are highly toxic and it isn't easy to tell them apart from harmless ones. Don't let your dog lick or nibble them.
How to stop your dog eating acorns
- Choose your route carefully. If the ground under a row of oaks or holm oaks is covered in acorns, take a different path or keep your dog on a short lead along that stretch.
- Practise "drop it" and "leave it". Swap whatever's in their mouth for a treat and reward them when they leave something on the ground. Practise at home first, then outside.
- Take treats with you. A dog that can earn something tasty from you pays more attention to you and less to the ground.
- Clear the garden. If you have an oak or holm oak nearby, rake up the acorns and leaves regularly.
- Consider a basket muzzle if your dog eats everything they find. Choose one they can pant and drink in, get them used to it gradually and, if in doubt, ask a dog trainer.
- Keep them busy at home. Let them use their nose: hide kibble around the house or serve their meals in a silicone slow feeder with 5 zones, so eating takes them longer. If they wolf their food down at home too, here's what to do if your dog eats too fast.
An acorn on the pavement is no reason to panic, but don't let your dog chew it. With a little attention on walks, you can both enjoy autumn without any scares.