# The foods that poison dogs, and the two where no safe amount is known > Chocolate and onions are the famous ones. Grapes and xylitol are the dangerous ones — for grapes there is no established toxic dose, and a single sugar-free sweet can drop a dog's blood sugar hard enough to collapse it. - **Publisher:** VOTVS (Fair coverage for everyone) — https://votvs.com - **Author:** VOTVS - **Published:** 2026-08-20 - **Language:** en - **Topic:** Animals - **Canonical URL:** https://votvs.com/en/articles/foods-poisonous-to-dogs - **Tags:** dogs, pets, animal health, poisoning - **Facts last verified:** 20 August 2026 --- **Call your vet now**, or a pet poison helpline. Do not wait for symptoms — with several of these, by the time a dog looks unwell the damage is under way. **Do not try to make the dog vomit.** The Royal Kennel Club is explicit that this can cause further harm. Tell the vet what was eaten, roughly how much, and when. Bring the packaging. Most owners know about chocolate. The two that actually catch people out are grapes and xylitol, because neither behaves the way people expect a poison to behave. ## The two with no reliable safe amount **Grapes, raisins, sultanas and currants.** VCA Animal Hospitals states there is **no well-established toxic dose** and no way to predict which dogs are more susceptible. Some dogs eat a handful with no effect. Others develop kidney failure. Dried forms are more concentrated and more dangerous, which matters because raisins turn up inside things — Christmas cake, mince pies, cereal bars, hot cross buns. The Royal Kennel Club notes kidney failure can be **delayed by up to three days**. **Xylitol.** A sweetener in sugar-free gum, mints, some peanut butters and some medicines. It causes a **rapid drop in blood sugar** and can cause **liver failure**. Signs are weakness, lethargy, collapse. The dangerous property here is portion size. A dog does not need to raid a cupboard. One or two pieces of gum from a handbag is a plausible dose. ## The rest of the list **Chocolate** — theobromine. Darker is worse; cooking chocolate and dark chocolate carry far more than milk. Vomiting and diarrhoea at lower doses, then excitability, twitching, tremors, seizures and heart problems. **Onions, garlic, leeks, shallots and chives** — the allium family damages red blood cells and causes anaemia. Watch for sleepiness, dullness, weakness, rapid breathing and discoloured urine. Cooked counts. So does gravy, stock and onion powder. **Macadamia nuts** — mechanism unknown. Weakness, drowsiness, an unsteady gait, pain, vomiting and tremors, typically within 12 hours. **Alcohol** — dogs are far more sensitive than people. Drowsiness, loss of coordination, low body temperature, low blood sugar, seizures, coma. **Raw bread dough** — expands in the stomach and ferments into alcohol. The Royal Kennel Club lists vomiting, retching, a visibly enlarged stomach, weakness, collapse and possibly death. **Blue cheese** — roquefortine C, from the fungus. Muscle tremors and seizures that may last up to two days. **Mouldy food** — the same problem. Mouldy dairy, bread and nuts are the ones to be careful about, including what is in an accessible bin or compost heap. **Cooked bones** — they splinter. Obstruction, gut irritation, or perforation of the stomach or intestinal wall requiring surgery. **Large amounts of sweets and sugar** — can trigger pancreatitis: loss of appetite, vomiting, diarrhoea, lethargy. ## What to tell the vet Four things, and having them ready saves time that matters: - **What** was eaten — the product name if you have it - **How much**, as best you can estimate - **When** - **Any symptoms** so far Bring the packaging. For chocolate, the cocoa percentage changes the calculation entirely, and the wrapper answers it faster than any description. ## Questions people ask ### How many grapes are dangerous for a dog? Unknown. VCA Animal Hospitals states there is no well-established toxic dose and no way to predict which dogs are more susceptible, so any amount warrants a call to a vet. Dried forms — raisins, sultanas, currants — are more toxic than fresh. ### Why is xylitol so dangerous to dogs? It causes a rapid drop in blood sugar and can lead to liver failure. It appears in sugar-free gum and sweets, some peanut butters and some medicines. The Royal Kennel Club lists weakness, lethargy and collapse as signs. ### Which chocolate is worst for dogs? The darker the worse. The toxic compound is theobromine, which is more concentrated in dark and cooking chocolate than in milk chocolate. Signs range from vomiting and diarrhoea to twitching, tremors, seizures and heart problems. ### Should you make a dog vomit if it eats something toxic? No. The Royal Kennel Club says never to attempt to induce vomiting, as it can cause additional harm. Call your vet, and tell them what was eaten, roughly how much, and when. ## Sources - Poisonous food for dogs — The Royal Kennel Club. https://www.royalkennelclub.com/health-and-dog-care/health-dog-care/health/health-and-care/a-z-of-health-and-care-issues/poisonous-food - Grape, raisin and currant poisoning in dogs — VCA Animal Hospitals. https://vcahospitals.com/know-your-pet/grape-raisin-and-currant-poisoning-in-dogs --- Published by VOTVS. Free to quote with attribution and a link to https://votvs.com/en/articles/foods-poisonous-to-dogs.