Halloween dangers

St Bernard laying down with two pumpkins

Halloween poses a number of health and welfare risks to dogs, from eating foods that can be toxic to man's best friend, such as chocolate and some sweets, to being scared by trick or treaters and children in costumes.


Chocolate contains a chemical called theobromine, which is poisonous to dogs, as well as other animals such as cats, rodents and rabbits. Generally speaking, the darker and more expensive the chocolate, the more theobromine it contains, and therefore the more poisonous it is. White chocolate contains very little theobromine and so is unlikely to cause chocolate poisoning, but is still very fatty and can make your dog ill. Chocolate can initially cause vomiting and diarrhoea, but is a stimulant and so can cause your dog to become excitable, as well as develop muscle twitching, tremors, fitting and life-threatening problems with their heart.


If available in large quantities, some dogs may gorge themselves on sugary sweets kept aside for, or collected by, trick or treaters. After eating lots of sugar, or even lots of fat, dogs can develop pancreatitis (an inflammation of the pancreas), which may cause them to be off their food, develop vomiting, diarrhoea, lethargy and go into organ failure. 

Sugar-free sweets

Some sugar-free sweets and chewing gums contain an artificial sweetener called xylitol, which can be very poisonous to dogs. Xylitol is more commonly found in food products in America, but is beginning to appear in sugar-free products in the UK as well. Xylitol can cause an otherwise healthy dog's blood sugar level to drop to dangerous levels and can also cause liver failure.

Obstruction risks

If eaten, sweet wrappers, lollipop sticks, food containers/boxes, or even small parts from a Halloween costume can all cause an obstruction in your dog's gut. This can be very dangerous and may require surgical intervention. Signs of an obstruction may include your dog being off their food, vomiting, lethargy and not defecating or finding it difficult to defecate.

What to do if your dog has eaten something it shouldn't

  • Consult your local veterinary practice immediately
  • It is important that your veterinary practice makes an informed decision as to whether your dog needs to be clinically assessed or treated. Where possible ensure that you tell them:
    • what your dog has eaten
    • how much has been eaten
    • when it was eaten     
  • Do not try and make your dog sick - trying to do this can sometimes cause other complications, which can make your dog unwell

Carved pumpkins

Keep all candles and candlelit, carved pumpkins out of the way of waggy tails and nosy noses. A knocked over candle may cause your dog to become burnt, or could start a house fire. Place any lit items on surfaces that are not likely to reached or jolted by your dog.

Trick or treaters

Frequent calls at the door from costumed trick or treaters may make your dog anxious or stressed. Think about how your dog is when you usually have visitors at the door, and take extra precautions to keep your dog calm and in a quiet and safe place throughout the evening. Masks and costumes can cause even the most familiar people to look and smell different to a dog, so if going out trick or treating, you may wish to leave your dog at home.

Tips for keeping your dog safe at Halloween

Taking a few simple precautions can ensure that Halloween is a happy and healthy time for dogs:

  • Keep chocolate out of reach of dogs. Chocolate contains a chemical called theobromine, which is poisonous to dogs. Eating chocolate can initially cause vomiting and diarrhoea, but is a stimulant and so can cause your dog to become excitable, as well as develop muscle twitching, tremors, fitting and life-threatening problems with their heart
  • Hide the sweets. If dogs get hold of a large quantity of sweets, such as those being stored for trick or treaters, they can develop an inflammation of the pancreas (known as pancreatitis) due to a sizeable ingestion of sugar. Sugar-free sweets can contain ingredients such as xylitol which can be poisonous to dogs, so it is important to keep these out of reach of your dog too
  • Be careful of lit pumpkins. Many people enjoy putting candles inside carved pumpkins, and dogs may inadvertently cause a fire or burn themselves if they knock one over with an overzealous nose or wagging tail. Never leave your dog unattended with a lit candle, even when it is inside a pumpkin
  • Beware of trick or treaters. Take extra care to ensure your dog is kept calm and happy. At Halloween it is not uncommon for strangers to knock at the door more frequently than usual, and in costume, so be aware that this can be stressful for the dog and ensure that they are kept in a quiet and safe place. For advice on how to keep your dog safe in unfamiliar situations, seek advice from a Kennel Club accredited instructor who are experts in dog behaviour and training
  • Be aware of choke hazards. At Halloween there are often more objects around that could obstruct a dog's airway if swallowed, such as sweet wrappers and small parts of costumes, or decorations and hard sweets, which could require surgical intervention. Signs of an obstruction could include your dog going off its food, vomiting, lethargy and finding it difficult to defecate or not defecating at all
  • Have the number of your dog's vet to hand. If your dog has eaten chocolate, lots of sweets or items which may obstruct its airway, contact your vet immediately for advice. They will need to know what was eaten, when and how much. If your dog eats something they shouldn't, do not attempt to make them sick unless your vet advises this, as this could cause further problems
  • Consider walking your dog at a different time. If your dog is usually walked in the early evening, consider changing the time of the walk on Halloween to make it a bit earlier or a bit later to avoid the rush of trick or treaters, who may scare your dog or cause unnecessary stress. Also be aware that fireworks are available before Halloween and loud bangs and sudden bright lights may spook your dog
  • Be aware of children. On Halloween, your dog is likely to come into contact with lots of children - probably more than usual - so it is important that you are aware of your dog's reaction to children and can prepare accordingly. Equally it is important to be prepared for children wanting to touch your dog, which can cause extra stress, particularly if the children are in costume and excitable 

Think your dog may be affected?

If you're worried about your dog's health, always contact your vet immediately!

We're not a veterinary organisation and so we can't give veterinary advice, but if you're worried about any of the issues raised in this article, please contact your local vet practice for further information.

Find a vet near you

If you're looking for a vet practice near you, why not visit the Royal College of Veterinary Surgeons' Find a Vet page.