Poisonous food

Dog laying on blanket

The dangers of human food

It is important to remember that some human foods can be very dangerous to dogs. If you wish to give your dog a treat, ensure that it is something dog friendly and avoid giving them any of the foods listed below.

Alcohol

Dogs are believed to be more sensitive to ethanol than humans and so drinking even a small amount of alcohol can cause effects. Certain alcoholic drinks may be more appealing to dogs, such as cream or egg based drinks. Dogs may develop similar effects to those expected in humans, including becoming drowsy, wobbly on their feet and in more severe cases they can develop low body temperature, low blood sugar, seizures and coma.

Blue cheese

Roquefort and other blue cheeses contain a substance called roquefortine C, which is a substance produced by the fungus used to make these cheeses. Dogs appear sensitive to this substance and in more extreme cases can cause dogs to quickly develop muscle tremors and seizures, which may last for up to two days.

Bones

When cooked, all bones become brittle and can easily splinter. Eating chicken, turkey or goose carcasses may cause larger pieces of bone to cause an obstruction, while smaller pieces may irritate the gut, or even penetrate the stomach or intestinal wall, which may require surgery. 

Safety tip: When preparing your Christmas Day meal, ensure that any meat is kept on the kitchen surface, or out of reach of your dog. When throwing away a carcass, take it to the outside bin, therefore avoiding any temptation for your dog to raid your kitchen bin during the night.

Bread dough

Raw bread dough containing live yeast can expand in the warm and moist environment of the stomach. As the bread dough rises, or increases in size, it can lead to bloat and may escalate to causing the stomach to twist. Signs may appear as vomiting, retching, the dog's stomach appearing bigger than usual, weakness, collapse and possibly even death. The dough can swell to such a degree that it may decrease blood supply to the stomach wall, or may put pressure on the diaphragm and could interfere with breathing.

Secondary problems: As well as the expanding dough causing problems, the multiplying yeast can start to produce alcohol. If absorbed into the blood, dogs may develop similar effects to those expected in humans, including becoming drowsy, wobbly on their feet and in more severe cases they can develop low body temperature, low blood sugar, seizures and coma.

Chocolate

Chocolate contains a chemical called theobromine which is poisonous to dogs and other animals. Generally speaking, the darker the chocolate, the more theobromine it contains, and therefore the more poisonous it is. White chocolate contains very little theobromine and although it is unlikely to cause theobromine poisoning, it is still very fatty and can make your dog ill. Chocolate poisoning can initially cause vomiting and diarrhoea, but may lead to excitability, twitching, tremors, fitting and life-threatening problems with the heart.

Chocolate at Christmas and Easter: each year, reports of dogs with chocolate poisoning increase dramatically around Christmas and Easter. During these periods take extra care to ensure that all chocolate is kept out of the reach of your dog. Although chocolate wrappers are not poisonous, they can cause an obstruction if eaten. This can be very dangerous and may require surgical intervention. Signs of an obstruction may include vomiting, lethargy, your dog being off their food, not defecating or finding it difficult to defecate.

Macadamia nuts

Why these nuts are poisonous to dogs is not known, but macadamia nuts can cause your dog to appear weak (particularly in their hind limbs), dull, sleepy and they can sometimes appear wobbly on their feet, or they may appear in pain or stiff when walking. Vomiting, tremors, lethargy and an increased body temperature can also occur. These effects usually appear within 12 hours and may last up to two days.

Some macadamia nuts are covered in chocolate and so pose a double risk to dogs.

Mouldy foods

Mouldy foods can contain lots of different toxins and, if eaten, may make your dog ill. One particular substance, which is mostly found on mouldy dairy products, bread and nuts, can cause dogs to quickly develop muscle tremors and seizures, which may last for up to two days. If you compost your food scraps, then make sure that they are kept outside in a sealed container that your dog cannot access.

Onions (Allium species)

Onions, garlic, leeks, shallots and chives all belong to the Allium family. These plants all contain a substance which can damage red blood cells in dogs and can cause life-threatening anaemia. Signs may not present for a few days, but can include stomach problems and may cause your dog to become sleepy, dull, weak, or develop rapid breathing. Poisoned dogs may also have discoloured urine. Ensure that your dog does not eat cooked foods that contain these vegetables, e.g. onion gravy, onion bhaji etc.

What about garlic capsules/supplements?

Based on current scientific findings, there is evidence to suggest that raw or cooked garlic is toxic to dogs. Therefore we would recommend that you do not feed your dog garlic unless it is in a licensed and authorised veterinary medicine or a supplement specifically formulated and produced for dogs (never give human supplements). Make sure the supplements are from a reputable source that has quality standards.

Raisins (fruits of the Vitis vinifera)

Grapes, raisins, currants and sultanas are all toxic to dogs and it is believed the dried forms of these fruits are more toxic. It is not known why these fruits are poisonous to dogs, or how much is dangerous. Some dogs have eaten large quantities of these fruit and experienced no ill effects, while others have become unwell after very small amounts. As well as possibly causing stomach problems, these fruits can cause kidney failure, which can sometimes be delayed by up to three days. Kidney failure may sometimes present as a decrease in urination, or your dog may also appear dull and show signs of increased thirst. Prompt treatment is important. If your dog does eat any amount, contact your veterinarian immediately.

It is important not to let your dog eat any foods that contain these fruits, such as hot cross buns, Christmas cake, Christmas pudding, fruit cake, mince pies, stollen etc.

Sweets/sugar

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. 

Xylitol

Some sugar-free sweets, sugar replacements, chewing gums, nicotine replacement gums and even some medicines, 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 to quickly drop to dangerous levels and larger amounts can also cause liver failure. Signs of poisoning can include your dog appearing weak, lethargic, or they may collapse or develop fits.

Tips on how to poison-proof your home

Keep all chocolate out of the reach of your dog. At Christmas, this includes chocolate coins hung from Christmas trees, advent calendars, boxes of chocolate put out on Christmas Day and don't forget the wrapped chocolate presents under your Christmas tree (just because its wrapped doesn't mean your dog can't smell it!).

What to do if you think your dog is poisoned

If you think that your dog may have eaten, touched or inhaled something that it shouldn't have, speak to your vet straight away.

Never try to make your dog sick. Trying to do this can cause other complications, which may harm your dog.

Things to tell your vet

In an emergency you can help your veterinary practice make an informed decision as to whether your dog needs to be treated by them and, if so, what the best treatment would be. Where possible you should provide your veterinary practice with the following information:

  • What poison you think your dog has been exposed to (i.e. chocolate, ibuprofen etc.). Include any product names, or lists of ingredients if relevant
  • How much they may have been exposed to (i.e. 500mg, 500ml, one tablet etc, even approximations may help)
  • When your dog was exposed to the poison (i.e. five minutes, five hours or five days ago)
  • If your dog has been unwell and, if so, what clinical effects have been seen

It is easier for a vet to care for a poisoned dog if it is treated sooner rather than later. If you are in any doubt, don't wait for your dog to become unwell before calling for advice.

What to take to your vets

If you do need to take your dog to your veterinary practice, make sure that you take along any relevant packaging, or a sample of the poison, e.g. parts of plant or fungi. Always make sure that you yourself are protected and cannot be poisoned in turn.

How to use this information

The information is intended to be used to prevent poisoning by raising awareness of certain poisons, rather than as a document to be used in an emergency. If you think that your dog has been poisoned, or has come into contact with potentially poisonous substances, contact your local veterinary practice immediately.

Think your dog may be affected?

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

We are 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.

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