Autumn is a wonderful time to get outside with your animal companions. Crunchy leaves, crisp walks, and cosy evenings at home all make the season special. But it also brings hidden hazards. From garden plants to festive treats, there are several toxins you need to be aware of that harm animal companions which are more common at this time of year.
Here’s our autumn safety guide to toxins that harm animal companions, so you can enjoy the season with peace of mind.
Conkers and Acorns
Those shiny conkers and scattered acorns are part of autumn’s charm, but they can cause problems for curious mouths.
- Conkers contain aesculin, a toxin that can trigger vomiting, diarrhoea, or more serious illness in large amounts.
- Acorns contain tannins, which may irritate the stomach, cause lethargy, and in rare cases, lead to kidney or liver damage.
If your animal companion swallows one, monitor them closely and call us if you notice any changes.


Mushrooms and Fungi
Autumn woodlands are full of mushrooms, and while some are harmless, others can be extremely toxic. The difficulty is that it’s almost impossible to tell them apart.
Toxic fungi can cause vomiting, diarrhoea, drooling, weakness, seizures, or worse. To stay safe, it’s best to stop your companion from nibbling mushrooms altogether. If they manage to eat one, get in touch with us straight away.


Plants and Berries
Some colourful autumn plants can sadly be harmful to animals.
Common risks include:
- Yew berries and foliage – these are highly toxic to cats and dogs.
- Ivy – can cause drooling, vomiting, or skin irritation.
- Horse chestnut leaves and seeds – another source of aesculin, like conkers.
If you’re planting for autumn colour, check that your choices are safe for your companions.



Human Treats and Seasonal Foods
Halloween and Bonfire Night bring plenty of sweet temptations. Unfortunately, many human treats contain toxins that harm animal companions.
- Chocolate – dangerous even in small amounts.
- Sweets containing xylitol – highly poisonous to dogs.
- Raisins, sultanas, and grapes – found in fruit cakes and bakes, can cause kidney failure.
- Onions and garlic – very common in our meals but toxic to cats and dogs.
Keep bowls of sweets and festive leftovers out of reach, and remind visiting trick-or-treaters not to share.




Rodenticides and Garden Chemicals
As the weather cools, rodents head indoors, and many households turn to rat or mouse poisons. These baits are extremely toxic to cats and dogs, causing internal bleeding or seizures if ingested.
Garden products like slug pellets and fertilisers also pose a risk. If you need to use them, always choose pet-safe versions and store them securely.


Antifreeze (Ethylene Glycol)
One of the most dangerous toxins that harm animal companions in autumn is antifreeze. Even tiny amounts can cause fatal kidney damage.
Cats are especially at risk because antifreeze tastes sweet, and they may lap it up from puddles or spills. Always clean up drips immediately and store bottles well out of reach.


What To Do If You’re Concerned
If you think your animal companion has eaten something toxic, don’t wait for symptoms, as some poisons act very quickly. While Jarden Vets will be opening in Olney from mid-October, you can still call us for advice and guidance in the meantime. If it’s an emergency before we open, please contact your nearest veterinary hospital straight away.
Protecting Animal Companions from Autumn Toxins
Autumn should be a season of fun, not worry. By being aware of the most common toxins that harm animal companions, you can keep your companions safe while still enjoying the season.
Jarden Vets will be opening in Olney this October, and we’ll be here to offer advice, reassurance, and expert care whenever you need us. In the meantime, if you’re worried your companion may have eaten something harmful, please don’t wait; give us a call on 01234 746325, and we’ll guide you on the next steps. Together, we’ll make sure your companions have a safe, happy autumn.
