As autumn arrives, countryside walks with your dog can be especially beautiful — but also carry hidden risks.

Certain flora and fungi become more abundant, and some can be toxic if sniffed, chewed, or eaten by curious canines. From fallen berries to mushrooms sprouting under hedgerows, dangers may lurk in places your dog loves to explore.

Even common favourites like acorns, conkers, or yew berries can cause serious illness. Staying alert, keeping dogs on leads in unfamiliar areas, and discouraging foraging are simple ways to keep them safe, so you both enjoy this season of mists and mellow fruitfulness

To help you stay alert, we asked the experts for their advice on the plants to look out for:

YEW

Commonly found in woodlands, hedgerows and graveyards, this evergreen tree is very dangerous for dogs. All parts are toxic (except the red berries), with the seeds being particularly potent. Symptoms to look out for include drooling and collapse.

yew tree with red berriespinterest
Margarita Vodopyanova//Getty Images

HORSE CHESTNUT

They may be synonymous with the season, but did you know that conkers – the seed of the horse chestnut tree – can cause significant illness in dogs. Found in cities and countryside alike, if eaten, conkers can cause vomiting, upset tummy and even intestinal blockages.

conkerspinterest
Anastasia Kibardina / 500px//Getty Images

ACORNS

Majestic oak trees support more life than any other tree, providing sustenance, shelter and a place to breed for a whopping 2,300 species. Its acorns are a favourite food source for woodland animals ranging from deer to squirrels; boars to badgers – but they’re deadly to dogs.

If eaten, acorns' toxic tannins can cause abdominal pain, lethargy and, in severe cases, kidney damage.

cluster of acorns in their cups on an oak treepinterest
Trudie Davidson//Getty Images

IVY

This ubiquitous plant flowers between September and November. Its berries – which can range from dark purple-black to orange-yellow in colour – are poisonous to pets, along with its leaves. If eaten in large amounts, its natural chemicals can irritate the digestive system and damage red blood cells – with symptoms including vomiting, abdominal pain and hypersalivation.

ivy, rural scene in woodland in west yorkshire, ukpinterest
Chris McLoughlin

FUNGI

In damp autumn months, fungi thrive in wet woodlands. The most dangerous for dogs are deadly deathcaps: a large mushroom (15 by 15cm) with an off-white stem found in mixed deciduous woods, particularly under birch and oak trees.

Other dangerous fungi include fly agaric – red capped with white spots – which grows in woodland and heathland on light soils among birch, pine or spruce. Plus, destroying angels, a rare, but deadly poisonous pure-white mushroom found on the ground in broadleaved and mixed woodland, especially birch woodland.

Ingestion of fungi can range from vomiting to diarrhoea to seizures, organ failure and even death. It's often very hard to tell harmless and deadly fungi apart, so best to avoid consumption completely.

red mushroompinterest
Pancake Pictures//Getty Images

What should you do if your dog has eaten a poisonous plant?

Emma Fisher, a vet for the People's Dispensary for Sick Animals (PDSA), tells Country Living: "Not all pets react to toxic plants in the same way – one animal may become very ill, while another might show no symptoms at all. To keep your pet safe, it's best to avoid poisonous plants altogether, no matter how toxic they are.

"The best way to keep your pet safe from toxic plants is to supervise them when they’re outside.

"If you think your dog has eaten something harmful, contact your vet immediately for advice or an emergency appointment. Never wait to see if your pet develops symptoms – waiting until they appear could be too late, because your dog may have already absorbed a harmful amount of toxin.

"Without prompt treatment, your dog could become seriously ill or even die. Even if you’re not sure whether what they ate is dangerous, it’s always safest to contact your vet for guidance and peace of mind."

12 easy-to-clean waterproof dog beds