Toxic foods for dogs: list, dangerous amounts, what to do

Nami is small and curious – we had to learn to keep everything out of her reach. Chocolate on the coffee table is off limits; she really would help herself.

The most dangerous foods for dogs are xylitol (birch sugar), chocolate and cocoa, grapes and raisins, onions and garlic, macadamia nuts, alcohol and caffeine. If your dog has eaten any of these: note the amount, the time and the packaging, and call your vet practice or a veterinary hospital straight away – don't try to make your dog vomit yourself. An 8 kg Jack Russell who has pinched a whole bar of dark chocolate from the Advent calendar is an emergency, not a case of “let's wait and see”.

This guide focuses on poisons, critical amounts and what to do in an emergency. What your dog can eat day to day – from apples to rusks – is covered in our A to Z list of foods.

This table doesn't replace a diagnosis, but it helps you assess the situation quickly. If your dog has eaten something dangerous: note the amount, the time and the packaging, and call your vet or a veterinary hospital.

Chocolate. The toxic substances are theobromine and caffeine. First symptoms such as vomiting, diarrhoea and thirst are possible from around 20 mg per kilogram of body weight, heart rhythm problems from around 40 to 50 mg/kg and seizures from around 60 mg/kg. Converted, that roughly means:

So a 10 kg dog who has eaten 100 g of dark chocolate is already in the range of possible heart problems – vet, immediately. Because theobromine is broken down only slowly in a dog's body, symptoms can take several hours to appear and can last a long time: restlessness, vomiting, a racing heart, trembling, seizures.

Grapes and raisins. The most treacherous item on this list: some dogs eat several grapes without any symptoms, while others develop acute kidney failure after just a few. Tartaric acid is now thought to be the likely cause, and its content varies widely. Even more than one grape or raisin per 4.5 kg of body weight can be a risk. Vomiting or diarrhoea often appear within 6 to 12 hours, kidney failure within one to three days. Raisins are also found in muesli, stollen and trail mix.

Onions, garlic, leeks, shallots, chives. Everything from the allium family destroys red blood cells and can lead to anaemia – raw, cooked, dried and as a powder. In dogs, symptoms have been described after 15 to 30 g of raw onion per kilogram of body weight, and garlic is about three to five times as potent. The tricky part: symptoms often only show after a few days. Leftovers in sauces, stocks and mince count too.

Avocado. The persin in avocado is mainly dangerous for birds, rabbits, horses and ruminants. For dogs, the flesh is less critical but very high in fat – and the large stone can get stuck in the intestines. Better to leave it out altogether.

Macadamia nuts. In dogs, symptoms have been described from as little as around 2.4 g per kilogram: weakness, trembling, vomiting, an unsteady gait. The symptoms usually subside within one to two days, but they still need to be checked by a vet. Other nuts are less toxic, but very high in fat and they can go mouldy – not a good idea either.

Xylitol (birch sugar, E 967). Especially dangerous because it's in so many products: sugar-free chewing gum, sweets, toothpaste, some peanut butters and reduced-sugar baked goods. From around 0.1 g per kilogram of body weight, dangerously low blood sugar can develop, and from around 0.5 g per kilogram, liver failure. For a small dog, just a few pieces of sugar-free chewing gum can be enough. Symptoms can begin within 30 minutes. Read the labels.

Alcohol. Also found in yeast dough (which keeps fermenting in the stomach), in chocolates and in forgotten dregs of beer on the balcony table. Even small amounts are dangerous for dogs.

Raw pork. Because of the Aujeszky's disease virus (pseudorabies). Domestic pigs in Germany have been considered free of it since 2003, but the virus still occurs in wild boar. For dogs, the infection is always fatal, and there is no vaccine. Thoroughly cooked pork, on the other hand, is not a problem.

Cooked bones, especially from poultry. They splinter into sharp fragments that can injure the digestive tract. Why raw bones aren't risk-free either is explained in our guide to raw bones for dogs.

Some kinds can go in the bowl, but have parts your dog shouldn't eat:

• Stone fruit such as cherries, plums, peaches and nectarines: stones, stalks and leaves contain precursors of hydrogen cyanide, and a swallowed stone can block the intestines. Only stoned flesh in small pieces.
• Tomatoes: unripe green fruit, stalks and leaves contain solanine and tomatine. Ripe red tomatoes without any green parts are fine in small amounts.
• Courgette and cucumber: if they taste bitter, they contain a lot of cucurbitacin – throw them away and don't feed them, even cooked.
• Apples and pears: the flesh makes a good snack, but the core and pips don't belong in the bowl.

First: stay calm, but act quickly. Second: write down exactly what was eaten, how much and when. Take the packaging or any leftovers with you.

Call straight away – in this order:

• Your vet practice
• The emergency vet service or a veterinary hospital in your area
• A poison information centre. In Germany, these are mainly there for people, but they also advise on animal poisonings when they have capacity – for example the Giftnotruf Bonn (0228 19240) or GIZ-Nord in Goettingen (0551 19240), both around the clock. GIZ-Nord has particular experience with animal poisonings.

Do NOT make your dog vomit without being told to. With some substances (acids, alkalis, sharp objects, foaming agents), that is more dangerous than the poisoning itself. You'll find home remedies such as salt water in many forums – don't use them, as they can cause salt poisoning.

Shortly after your dog has eaten something toxic, the vet practice can induce vomiting in a controlled way. Later on, depending on the poison, treatments such as activated charcoal, drips and monitoring are used.

If your dog is already showing symptoms such as vomiting, diarrhoea or abdominal pain, our guide to stomach and gut problems in dogs lists the warning signs that mean you shouldn't wait.

Chocolate, sweets and baking ingredients belong in closed cupboards – not on the coffee table. Bins should have lids and be out of reach. Take grapes and raisins out of the fruit bowl if your dog can get to it. Only give peanut butter without xylitol (check the label). Tell your guests: “Please don't give anything from the table.” Which fruit makes a good snack instead is explained in which fruit is healthy for dogs.

By the way: a photo of the suspect food's packaging on your phone is worth its weight in gold if you can no longer remember later what was in it.

In the DoggoMeal app, you can see straight away for every ingredient whether it's OK for your dog. Get the app here.