Autumn & Winter Health Hazards for Dogs
As the weather turns colder (bar the most recent heatwave!) and the nights draw in, autumn and winter can bring adventures for our dogs — long woodland walks, muddy puddles, and cosy evenings at home.
But the change in seasons also comes with a few hidden hazards that can catch owners off guard. Being aware of them means you can keep your dog happy, healthy, and safe through the colder months.
Conkers & Acorns
Both conkers and acorns are toxic to dogs if eaten. They can cause vomiting, diarrhoea, abdominal pain, and even serious poisoning in large amounts.
Dogs may pick them up out of curiosity or play, so keep an eye out on walks — especially if your dog likes to scavenge or carry things in their mouth.
Tip: Practise a reliable “leave it” or “drop” cue to help avoid accidental ingestion.
Mushrooms & Fungi
Autumn is prime mushroom season — and while some are harmless, others can be highly toxic. It’s often impossible to tell the difference, so the safest rule is to avoid all wild mushrooms.
If your dog eats a mushroom or shows sudden vomiting, drooling, or wobbliness, contact your vet immediately.
Antifreeze & De-icer
Antifreeze (ethylene glycol) is one of the most dangerous winter substances for dogs. Even small amounts, such as licks from a puddle under a car, can be fatal.
Keep bottles securely stored, wipe up any spills straight away, and never let your dog drink from roadside puddles.
If you suspect antifreeze poisoning, it’s a medical emergency! Contact your vet immediately.
Festive Foods
Halloween and Christmas bring all sorts of tasty human treats, but many are unsafe for dogs. Watch out for:
Chocolate (toxic even in small amounts)
Onions, leeks, and garlic (often found in stews and stuffing)
Grapes and raisins (including mince pies and Christmas cake)
Xylitol (found in sugar-free products)
Keep festive snacks well out of reach, and remind guests not to share their food, no matter how persuasive those puppy eyes are. Be especially aware on walks around Halloween.
Fireworks Night
Fireworks season can be a particularly stressful time for dogs, with unexpected bangs, flashes, and changes to their usual routine. Even dogs who have previously coped well may find the experience overwhelming.
Preparation is key. Plan ahead by creating a comfortable, secure safe space at home, keeping windows and curtains closed, and using background noise to help muffle the sounds. Walk your dog during daylight where possible, ensure they are securely harnessed and on lead outdoors around this time.
Remember that forcing a frightened dog to face their fears can make things worse. Instead, allow them to choose where they feel safest and offer reassurance if they seek comfort from you.
For more practical advice on preparing your dog for fireworks, read my existing blog post on fireworks safety for dogs.
Tip: If your dog experiences significant fear or anxiety around fireworks, speak to your vet well in advance. There are welfare-friendly ways to help them cope, and support is best arranged before fireworks season begins.
Wet Leaves & Mould
Fallen leaves are great for sniffing and exploring, but piles of damp, decomposing leaves can harbour mould and fungi that may be harmful to dogs. Some moulds produce mycotoxins, which can cause serious illness if ingested.
Dogs who enjoy scavenging, chewing sticks, or rummaging through leaf piles may be more at risk, particularly if they eat mouldy vegetation.
If you have a dog that suffers with seasonal allergies, be aware that they could also be sensitive to mould. Make sure you are either wiping them down after walks, paying special attention to paws, bellies and legs, or using something like an Equifleece to protect and keep them dry and clean easier.
Tip: Keep an eye on what your dog is sniffing and eating, and discourage them from chewing or swallowing decomposing leaves. Be particularly cautious around large piles of wet leaves that have been left to rot.
If your dog eats mouldy material and develops vomiting, tremors, wobbliness, or unusual behaviour, contact your vet immediately.
Cold & Freezing Weather
Short-haired, young, elderly, or underweight dogs are more vulnerable to the cold. Limit time outdoors in freezing weather, and consider a well-fitting coat to keep them warm on walks.
After snowy walks, check paws for compacted snow, grit, or salt — these can cause irritation or small cuts. Rinse paws with warm water and dry them gently when you get home.
Indoor Hazards
As we spend more time indoors, it’s worth thinking about home safety too.
Candles and open fires
Electric blankets or heaters
Some winter-scented essential oils and diffusers are toxic to pets (like tea tree, cinnamon, and clove)
Keep your dog’s environment cosy, but safe.
Hydration Still Matters
It’s easy to forget hydration when it’s cold, but dogs still need access to fresh water at all times — especially if they’re eating dry food or spending time near heating.
Some dogs even prefer slightly warm water in winter — experiment and see what they like best.
Stay Safe, Stay Cosy
Autumn and winter are magical seasons to enjoy with your dog — as long as you stay aware of the hidden dangers that come with them.
Small management changes can make a big difference to your dog’s comfort and safety — and help you both enjoy the season to the fullest.
👉 If your dog struggles with the change in routine, darkness, or weather, I can help. Book a discovery call with Trained by Scarlet Dog Training to create a tailored plan that supports your dog’s wellbeing year-round.