Foods Toxic to Dogs: The Complete List and What to Do

The foods most likely to seriously poison a dog are chocolate, xylitol (also sold as birch sugar), grapes and raisins, onions, garlic and other alliums, macadamia nuts, alcohol, caffeine and raw yeast dough. Cooked bones and fruit stones are dangerous in a different way: they break teeth and block or tear the gut. If your dog has eaten any of these, call your vet or a pet poison helpline now. Don’t wait for symptoms, because several of these poisons cause no signs for hours or days.

Quick reference: toxic foods, symptoms and urgency

Chocolate: how much is too much?

Chocolate contains methylxanthines, mainly theobromine with some caffeine.

The Merck Veterinary Manual gives these approximate thresholds for theobromine plus caffeine combined:

• About 20 mg per kg of body weight (9 mg per lb): mild signs such as vomiting, diarrhoea and excessive thirst.
• 40–50 mg/kg (18–23 mg/lb): effects on the heart, such as a fast or irregular heartbeat.
• 60 mg/kg or more (27 mg/lb): seizures are possible.

Merck puts the lethal dose at 100–200 mg/kg but notes that severe illness and death can happen at lower doses, so treat these as rough markers rather than safe limits.

The type of chocolate matters as much as the amount. Merck lists these approximate methylxanthine levels:

A worked example shows why this matters. A 10 kg (22 lb) dog that eats a 50 g (1.8 oz) bar of dark chocolate takes in roughly 275 mg, or about 27 mg/kg. That is past the threshold for vomiting and restlessness. The same dog eating 50 g of milk chocolate gets about 115 mg, or 11–12 mg/kg, which is less likely to cause serious signs but still worth a call. Cocoa powder and baking chocolate can reach the seizure range in surprisingly small amounts. Real products vary, so let the helpline or your vet do the maths with you.

Signs usually appear 6–12 hours after eating and can last up to 72 hours in severe cases. Cocoa bean mulch, used in some gardens, contains the same compounds.

Xylitol (birch sugar): the fastest-acting danger

Xylitol is a sugar substitute. In people it barely touches blood sugar. In dogs it causes a rapid insulin surge, and blood sugar can drop dangerously within 10 to 60 minutes, according to the US FDA. Signs are vomiting, then weakness, staggering, collapse and seizures.

Merck links doses above roughly 100 mg/kg (0.1 g/kg) with low blood sugar and doses above about 500 mg/kg with liver injury in some dogs. Liver damage may not show until 24–48 hours later, so dogs often need monitoring even when they seem well at first.

Check labels for xylitol, birch sugar or wood sugar. It turns up in:

• Sugar-free gum, mints and sweets
• Some peanut and nut butters
• Sugar-free baked goods and desserts
• Human toothpaste and mouthwash
• Chewable vitamins and some liquid medicines

A handbag on the floor with a pack of gum in it is the classic scenario.

Grapes, raisins and the tartaric acid discovery

Grapes and raisins can cause acute kidney injury in dogs. For years the cause was a mystery, and so was the strange pattern where some dogs ate a bunch without harm while others went into kidney failure after a handful.

The leading explanation now is tartaric acid. Around 2021, toxicologists at the ASPCA Animal Poison Control Center proposed it after noticing that dogs who ate cream of tartar (potassium bitartrate, a common ingredient in homemade playdough) developed a very similar kidney injury. Tamarind, another fruit rich in tartaric acid, has since been linked to the same problem. The ASPCA now lists tartaric acid as the suspected toxin, and the current Merck Veterinary Manual names it as the proposed toxic principle, explaining that dogs appear to lack certain transporters that would clear it from kidney cells.

Merck notes that tartaric acid content varies between fruits, which would explain the unpredictability. The evidence is strong but not final, it doesn’t tell you which grape is safe, and it puts tamarind and cream of tartar on the avoid list too.

What we know for practical purposes:

• Merck notes that more than one grape or raisin per 4.5 kg (10 lb) of body weight may be a risk to the kidneys. There is no known safe amount.
• Sultanas and Zante currants (the dried fruit in many cakes, buns and mince pies) count as raisins. True currants from Ribes bushes, such as blackcurrants, have not been linked to kidney injury.
• Vomiting or diarrhoea usually starts within 6–12 hours. Kidney failure can follow over 24–72 hours.
• Once a dog stops producing urine, the outlook is poor without dialysis. Early decontamination and IV fluids for at least 48 hours give the best chance.

Onions, garlic and other alliums

Onions, garlic, leeks, shallots, chives and spring onions contain sulfur compounds that damage red blood cells, leading to a type of anaemia. Merck reports signs in dogs after about 15–30 g of raw onion per kg of body weight, and notes that garlic is roughly 3–5 times more toxic than onion.

Cooking doesn’t make alliums safe. Dried onion and garlic powder are concentrated and turn up in gravy, stock cubes, soup mixes, seasoned meat and some baby foods. The damage is delayed: anaemia usually becomes obvious 3–5 days after eating, so a dog that seemed fine after the barbecue can turn pale and weak later in the week. Watch for pale gums, tiredness, fast breathing and dark or reddish urine.

Macadamia nuts

Macadamias cause weakness (often in the back legs), wobbliness, tremors, vomiting and a raised body temperature. Merck reports signs after about 2.4 g/kg, which is only a few nuts for a small dog. Signs usually start within 12 hours and settle within 12–48 hours. It is rarely fatal, but chocolate-coated macadamias add a second poison, so call for advice.

Other nuts such as almonds, pecans and walnuts aren’t toxic in the same way. Their high fat content can still cause vomiting and diarrhoea and may trigger pancreatitis, according to the ASPCA.

Alcohol, caffeine and raw dough

Alcohol is absorbed fast. Dogs can develop vomiting, poor coordination, low blood sugar, low body temperature, slow breathing and coma. Sweet cocktails, cream liqueurs and fermenting fruit all count.

Caffeine works like the theobromine in chocolate. Coffee grounds, tea bags, energy drinks and caffeine tablets are the concentrated sources; a lick of a latte is a different story from a chewed packet of pills.

Raw yeast dough is a double hazard. The Pet Poison Helpline explains that it expands in the warm stomach, which can stretch it and, at worst, lead to gastric dilatation-volvulus (a twisted stomach). Meanwhile the yeast ferments sugars into alcohol. Signs include a swollen belly, retching without bringing anything up, and drunken behaviour. Baked bread doesn’t carry the same risk.

Avocado: less scary than its reputation

Avocado contains persin, which is genuinely dangerous to birds, rabbits, horses, goats and sheep. The ASPCA and the Pet Poison Helpline both say dogs are much less affected. For dogs, the realistic risks are the stone (a common cause of gut blockage) and the fatty flesh upsetting the stomach. Keep the stones away, and treat guacamole as a no because it usually contains onion or garlic.

Cooked bones and other things that cause physical damage

Not every dangerous food is a poison. Cooked bones become brittle and can splinter, causing mouth injuries, choking, constipation, blockages or perforations of the gut. The ASPCA notes that raw bones also carry obstruction risks and can require surgery. Fruit stones, corn cobs and kebab skewers left with meat on them cause similar problems.

Signs of a blockage include repeated vomiting, retching, refusing food, a painful belly and straining to pass faeces. These can appear a day or more after the bone disappears.

What to do if your dog eats something toxic

1. Take it away and note the details. What it was, roughly how much, and when. Keep the packet or wrapper.
2. Weigh your dog, or estimate. Toxic doses are calculated per kg or lb.
3. Call your vet or a poison helpline straight away. Many poisons are treatable when caught early and much harder once signs develop.
4. Don’t make your dog vomit unless you are told to. Vets use dog-specific drugs to do this, and vomiting is the wrong choice for some substances and for dogs that are already drowsy or seizing.
5. Don’t give milk, oil or salt. Salt is itself a poison in dogs.
6. Go in if advised. Bring the packaging.

See a vet now if:

• Your dog has eaten anything containing xylitol, any amount of grapes or raisins, or raw dough
• Your dog is trembling, staggering, collapsing or having a seizure
• Your dog’s belly is swelling, or it is retching without bringing anything up
• The gums look pale, white or bluish
• Your dog has eaten dark chocolate, baking chocolate or cocoa powder and is small
• You can’t reach a helpline and aren’t sure

Pet poison helplines by country

These services are staffed by veterinary toxicology specialists. Most charge a consultation fee, and fees change, so check their websites. Your own vet or nearest emergency clinic is always an option, and in many countries it’s the only one.

The Animal Poisons Helpline website also lists numbers for callers in the US, Canada and Singapore. If you live elsewhere, including Ireland, Canada, India and most of the EU, save your vet’s out-of-hours number and the nearest 24-hour emergency clinic in your phone today, before you need them.

Treatment can mean induced vomiting, activated charcoal, blood tests and days on IV fluids, and costs vary a great deal by country and clinic.

The bottom line

Xylitol, grapes and raisins, chocolate, alliums, macadamias, alcohol, caffeine and raw dough are the foods to keep out of reach, and cooked bones and fruit stones belong in a bin with a lid. The dose matters for some of these, but grapes and xylitol can hurt dogs at amounts that look trivial. If your dog eats something on this list, call your vet or a poison helpline before symptoms start, with the product, the amount and your dog’s weight to hand. Put the helpline number for your country in your phone now.