Yes, acorns are poisonous to dogs. They contain tannins, which can irritate the stomach and, in larger amounts, may cause more serious illness. Acorns are also hard and can create a choking risk or an intestinal blockage if swallowed whole. Conkers are unsafe too: they contain toxic compounds and their size and smooth, hard shape make them a particular obstruction risk.

If your dog has eaten an acorn or conker, remove any remaining pieces and contact your vet for advice, particularly if they have swallowed a whole conker, eaten several acorns, are small, or seem unwell. Don’t try to make your dog sick unless a veterinary professional specifically tells you to.

Early autumn is a good time to refresh recall and “leave it” skills. A pocketful of small, appealing rewards gives you something useful to trade for whatever your dog has found, rather than turning a woodland walk into a chase.

Why are acorns poisonous to dogs?

Acorns come from oak trees and contain tannins. These naturally occurring substances are most concentrated in unripe, green acorns, but fallen brown acorns should not be treated as safe. Dogs can react differently depending on their size, how many they have eaten and whether they have chewed or swallowed them whole.

After eating acorns, a dog may develop digestive upset such as drooling, vomiting, diarrhoea, tummy pain or reduced appetite. In more significant cases, tannin exposure can affect the kidneys or liver. A swallowed acorn can also become lodged in the gut, especially in a puppy or small dog.

One tiny, chewed fragment is not always an emergency, but it is never something to ignore. Ring your vet or, out of hours, your usual emergency veterinary service for case-specific advice. Be ready to say what your dog ate, roughly how much, when it happened and whether they swallowed it whole.

Are conkers poisonous to dogs?

Yes. Conkers are the seeds of the horse chestnut tree. They contain compounds that can be toxic to dogs, and the outer casing and the conker itself may both cause irritation if chewed. A whole conker is also an awkward size and shape: it can choke a dog or cause a blockage in the stomach or intestines.

Conkers are often especially tempting because dogs can pick them up and carry them like a ball. Don’t allow this as a game, even if your dog appears to be holding rather than eating one. A playful toss, a sudden gulp or a dog trying to protect their find can quickly turn it into a veterinary problem.

Signs to watch for after eating an acorn or conker

Symptoms vary, and some signs may not appear straight away. Contact a vet promptly if you know your dog has eaten either item, and seek urgent advice if you notice:

• vomiting, diarrhoea or repeated retching;
• excessive drooling;
• tummy pain, a hunched posture or a swollen-looking abdomen;
• tiredness, weakness or seeming unusually quiet;
• wobbliness, tremors or collapse;
• straining to poo, inability to keep food or water down, or other signs that could suggest a blockage.

Take a photo of the item or bring a similar one with you if it is safe to do so. It can help the veterinary team identify what has been eaten. Do not delay a call while waiting for symptoms if your dog has swallowed a whole conker or several acorns.

What to do if your dog eats an acorn or conker

1. Stay calm and prevent access to more. Move your dog away from the tree or pile of fallen nuts, using a lead if needed.
2. Check their mouth only if it is safe. If a loose piece is clearly visible and easily removed, take it out gently. Never put your fingers deep into a dog’s mouth or attempt to retrieve something they may bite down on.
3. Call your vet. Tell them your dog’s approximate weight, the item, the likely amount and whether it was swallowed whole.
4. Follow the advice you are given. Keep your dog quiet and monitor them closely. Do not offer home remedies or induce vomiting without instruction.
5. Keep future walks simple while you wait for advice. Avoid food, treats or water only if your vet advises it; otherwise, maintain normal access to fresh water.

Making autumn walks less tempting for scavengers

You cannot clear every acorn from a park or woodland path, but a few routine changes make a real difference. Keep a closer lead near oak and horse chestnut trees, particularly after wind or rain when the ground is covered. Let your dog sniff, but avoid allowing them to hoover through leaf piles where acorns and conkers are hidden.

A well-practised “leave it” cue is useful, but management matters just as much. If your dog is quick to grab and swallow things, a shorter lead in high-risk areas is kinder and safer than repeatedly asking for a cue they cannot yet manage. A properly fitted basket muzzle can be worth discussing with a qualified trainer for persistent scavengers; it should allow panting, drinking and taking small rewards, and needs gradual, positive introduction.

A practical treat-and-trade routine

Carry small rewards that your dog can eat quickly. The aim is not to fill them up on a walk; it is to give them a better reason to turn away from the ground and come back to you.

• Start at home or in a quiet area: say “leave it”, then reward the moment your dog turns away from a low-value object.
• On walks, reward check-ins before your dog reaches an acorn or conker.
• If they pick something up, avoid chasing. Call them cheerfully, offer a higher-value treat close to their nose and trade as they release the item.
• Reward the drop, then move away from the area. Repeatedly snatching things away can make some dogs swallow faster next time.

Small, single-protein natural treats can be handy for this job because they are easy to portion and keep in a treat pouch. Choose a reward your dog genuinely enjoys, break it into pea-sized pieces where appropriate, and factor treats into their daily food intake. You can view our natural dog treats for training-sized options and larger chews suited to different chewing styles.

Choosing safe treats for woodland training

For recall and “leave it” work, soft or easily breakable treats are usually more practical than a long-lasting chew. You want your dog to take the reward, swallow safely and be ready to listen again, not settle down to chew while you are beside a path full of conkers.

Pick a size that suits your dog, supervise anything that needs chewing and always carry water on longer walks. Avoid giving cooked bones, and remove small end pieces of any chew if they become a swallowing hazard. If your dog has known food sensitivities, choose a protein they already tolerate rather than introducing several new treats during the same week.

At Raw Dogs Dorset, we can help owners choose natural rewards based on a dog’s size and usual chewing style. If you are also considering a change from kibble to raw meals, our guide to starting raw feeding is a straightforward place to begin.

Frequently asked questions

Can dogs eat old or brown acorns?

No. Acorns should be avoided whether they are green, brown, fresh or weathered. Older acorns can still be chewed or swallowed and may cause stomach upset or a blockage.

What happens if my dog eats one acorn?

Some dogs may have no obvious reaction to a small piece, but it is sensible to call your vet for advice. The risk depends on your dog’s size, the amount eaten and whether the acorn was swallowed whole. Monitor for vomiting, diarrhoea, pain or changes in behaviour.

Are conker shells poisonous to dogs?

The shell and husk should be treated as unsafe as well. They can irritate the mouth and stomach, and pieces may be swallowed. Keep your dog away from both fallen conkers and their spiky outer cases.

Can I use treats to stop my dog eating things outside?

Treats can support training, recall and a calm trade, but they do not replace supervision. Use high-value, small rewards to practise “leave it” and reward your dog for choosing you, while managing access around hazards.

Safer rewards, calmer autumn walks

Acorns and conkers are part of a British autumn, but neither belongs in a dog’s mouth. Keep walks enjoyable by planning ahead: take suitable rewards, practise a reliable trade, and use a lead in the areas where your dog is most likely to scavenge.

For practical help choosing small natural rewards for recall and “leave it” work, explore Raw Dogs Dorset’s natural dog treats. We offer nationwide online delivery, and local collection is available from Moordown and Blandford.