Autumn is here, and with it come roasted chestnuts from street stalls, chestnut festivals and country walks past open, spiky husks on the ground. So it's only natural to wonder: can dogs eat chestnuts? Especially when yours is staring at you while you peel them. The short answer: the chestnut itself isn't toxic, but how you give it and how much really matter. And there's an almost identical-looking seed, the horse chestnut or conker, that is toxic and litters parks and tree-lined streets in many towns and cities.
Can dogs eat chestnuts? Yes, cooked and peeled
The true sweet chestnut (Castanea sativa) is rich in starch and fibre and low in fat. It works as an occasional treat for your dog as long as you stick to three rules:
- Cooked. Boiled or roasted, with no salt, sugar or butter. Raw chestnuts are hard, full of tannins and difficult to digest: they can easily lead to bloating, wind or diarrhoea.
- Fully peeled. Remove the shell and also the thin inner skin, which is bitter and astringent. The shell can't be digested and, in small dogs, can cause an intestinal blockage.
- In small pieces. A whole chestnut can choke a dog that swallows without chewing. Chop or mash it.
How many? As a rough guide, half to one for a small dog and two or three for a medium or large dog, and not every day. Treats shouldn't make up more than 10% of daily calories, and chestnuts are more calorific than they look. If your dog is overweight or diabetic, it's best to skip them: they're essentially concentrated starch.
A tip to make them last: crumble the cooked chestnut into the grooves of a silicone slow feeder. The treat turns into a little sniffing game instead of vanishing in a second.
Horse chestnuts and dogs: the real danger is in the park
The horse chestnut (Aesculus hippocastanum) lines many avenues and public gardens, and in September and October it covers pavements with shiny brown seeds, conkers, that look just like chestnuts. They have nothing to do with the ones we eat: they contain aescin and other saponins that irritate the digestive tract. And, being round and hard-skinned, they're perfect for a playful dog to pick up, chew or swallow.
Telling them apart is easy once you know what to look for:
- Edible sweet chestnut: it has a pointed tip with a small tuft and at least one flat side; the husk is covered in fine, dense spines and usually holds two or three nuts.
- Horse chestnut: a round, smooth seed with no tip and a large pale patch; the green case has a few short, widely spaced spikes (or none at all) and usually contains a single seed.
Symptoms and what to do if your dog has eaten one
If your dog has swallowed a horse chestnut, vomiting, diarrhoea, abdominal pain, excessive drooling, restlessness or, on the contrary, lethargy usually appear within a few hours. If it went down whole, there's also a risk of intestinal blockage, which shows up as repeated vomiting, a tense belly and no stools over the following days.
- Call your vet straight away and tell them what your dog ate, how much and when. If you can, take a similar seed with you.
- Don't try to make your dog sick yourself, and never with salt water: it's dangerous and can cause salt poisoning.
- Keep an eye on their poo for two or three days to make sure the seed has passed.
The same goes for real chestnuts eaten raw with their shell, or for a chewed husk: the spines get stuck in the mouth and throat and should be removed by a vet.
Marrons glacés, chestnut purée and other autumn treats
Here the problem isn't the chestnut but everything else. Marrons glacés, sweetened chestnut purée and chestnuts in syrup are loaded with sugar. And watch out for autumn cakes and breads made with raisins: raisins are toxic to dogs even in small amounts and can damage their kidneys. No tasting from your plate, not even a tiny bite.
Autumn walks without scares
- Under horse chestnut trees, keep your dog on a short lead, especially if they're young and pick everything up.
- Teach or brush up on the “drop it” command, with a treat that's better than whatever is in their mouth.
- Don't throw chestnuts or conkers for your dog like balls: it's the quickest way for them to swallow one.
- After a walk through chestnut woods, check their paws and between the pads: that's where husk spines get stuck.
In short: a few cooked, peeled chestnuts cut into small pieces are an autumn treat your dog can enjoy. Conkers from the park, spiky husks and seasonal sweets, on the other hand, should stay well out of reach.