Top Foods You Should Never Feed Your Dog

Grapes, Raisins, Sultanas, and Currants

Grapes and all dried grape products are acutely toxic to dogs and can cause sudden kidney failure — even in very small amounts. The toxic compound has not been definitively identified, which means there is no established safe dose. Some dogs have eaten grapes without apparent effect, while others have developed kidney failure after a single grape. The unpredictability makes this one of the most important foods to keep out of reach.

Signs of grape toxicity include vomiting within the first few hours, followed by lethargy, reduced urination or no urination, abdominal pain, and eventually kidney failure if untreated. Treatment is most effective when started within 1–2 hours of ingestion. Contact your vet immediately if your dog eats any amount of grapes or raisins.

Chocolate, Coffee, and Caffeine

Chocolate contains theobromine, a compound dogs metabolise much more slowly than humans. The darker the chocolate, the more theobromine it contains — dark chocolate and baking chocolate are the most dangerous; milk chocolate is moderately toxic; white chocolate has very little. Symptoms of chocolate poisoning include vomiting, diarrhoea, restlessness, rapid breathing, muscle tremors, and seizures.

Coffee, tea, energy drinks, and any product containing caffeine carry similar risks. Never leave chocolate in reach of dogs, particularly during Easter and Christmas when large quantities enter the home. Call your vet immediately if you suspect chocolate ingestion — provide the dog's weight, the type of chocolate, and the approximate amount eaten.

Onions, Garlic, Leeks, and All Alliums

All members of the allium family — onions, garlic, leeks, chives, shallots, and spring onions — are toxic to dogs. They contain organosulphur compounds that damage the oxygen-carrying haemoglobin in red blood cells, causing a condition called haemolytic anaemia. Garlic is approximately five times more potent than onion per gram.

Danger does not require a large amount: regular small doses (as from a dog repeatedly eating food scraps seasoned with onion or garlic) can accumulate to toxic levels over time. Cooked, raw, dried, or powdered forms are all equally toxic. Symptoms include pale or yellowish gums, weakness, reduced appetite, reddish or orange-tinged urine, and rapid breathing. These symptoms may appear days after ingestion as anaemia develops.

Xylitol (Found in Sugar-Free Products)

Xylitol is a sugar alcohol sweetener found in some sugar-free chewing gum, sweets, peanut butters, and baked goods. In dogs, xylitol causes a rapid and severe release of insulin from the pancreas, leading to life-threatening hypoglycaemia (blood sugar crash) within 15–30 minutes. Some dogs also develop acute liver failure. Xylitol is one of the most acutely dangerous household substances for dogs relative to body weight.

Symptoms include sudden weakness, trembling, loss of coordination, vomiting, seizures, and collapse. Check peanut butter labels carefully — some brands use xylitol as a sweetener; give only xylitol-free peanut butter to dogs. Check labels on any sugar-free product before giving to your dog. If your dog eats anything containing xylitol, treat it as an emergency and go to the vet immediately.

Macadamia Nuts, Cooked Bones, Avocado, and Alcohol

Macadamia nuts cause a distinctive syndrome in dogs: weakness in the hindquarters, muscle tremors, vomiting, and fever, typically appearing within 12 hours. The mechanism is unknown, but the syndrome is well-documented. Most dogs recover with supportive care, but veterinary assessment is important.

Cooked bones — particularly small bones from chicken, fish, or chops — can splinter into sharp shards that cause mouth lacerations, intestinal perforations, or blockages. Raw bones are generally safer but still carry risk; always supervise bone chewing.

Avocado contains persin, which causes vomiting and diarrhoea in dogs and is more dangerous to birds and other animals. Alcohol in any form — wine, beer, spirits, or food containing alcohol — is acutely toxic to dogs and can cause coma and death even in small amounts relative to body weight.