The Dangers Of Acorns & Conkers

Autumn is my favourite time of year, but it can also be one of the most stressful if you’ve got a curious dog who loves to explore the world with their mouth and nose!

This is the season where trees and bushes shed their leaves, seeds, berries, and nuts. While most are harmless, two we must be extra cautious of are:

• Oak trees (Quercus) – drop acorns

• Horse Chestnut trees (Aesculus hippocastanum) – drop conkers

Both can pose serious risks if eaten by dogs.

Why They’re Dangerous

• Acorns contain tannins, which are toxic and can cause anything from mild tummy upset to kidney or liver failure (which can be fatal).

• Conkers contain aesculin, which can cause vomiting, diarrhoea, and in severe cases, bloody diarrhoea and vomiting.

• Both can also be a choking hazard or cause an intestinal blockage that may require surgery.

When to Watch (seasonality)

• Peak risk: late summer → autumn (roughly August–November in the UK).

• Lingering risk: acorns and conkers can stay on the ground for months after falling, so you may still find them into December and beyond.

• Higher-risk times: after windy days or storms (more debris falls), and during busy wildlife activity when things get scattered.

Keep this timeframe in mind for extra vigilance, especially on walks and in gardens.

Signs of Acorn Poisoning

Mild to moderate symptoms:

• Vomiting

• Bloating

• Diarrhoea

• Stomach upset

• Loss of appetite

• Drooling

• Lethargy

• Collapse

• Dizziness

• Retching

Severe cases may lead to:

• Kidney failure

• Toxic shock

• Liver damage

• Death

Signs of Conker Poisoning

• Vomiting (may contain blood)

• Diarrhoea

• Drooling

• Abdominal pain

• Increased thirst

• Loss of appetite

• Restlessness

• Wobbliness / unsteady walk

• Muscle tremors

What To Do If your dog eats an acorn or conker:

• Contact your vet immediately.

• Vets may induce vomiting and perform gastric lavage to remove toxins.

• Do not try to make your dog vomit at home unless instructed by your vet.

Prevention Tips

• Practice leave it, drop it, trade — these cues can literally save lives.

• Keep scavenger dogs on lead near oak or horse chestnut trees.

• Do garden sweeps if you have these trees nearby

• Carry high-value treats on walks for quick trades.

• Be extra vigilant after windy days or storms when more acorns/conkers may be around.

• Remember: wildlife can carry and drop them into your garden, even if you don’t have these trees yourself.

Even though autumn is full of crunchy leaves and cosy walks, it pays to be mindful of what’s under our dogs’ noses. With a bit of awareness and preparation, we can all enjoy the season safely.

© Written by Kayleigh Adams for NO BULL Just Natural Health for Dogs.