What foods should dogs never eat?
Dogs should never eat chocolate, grapes, raisins, xylitol, garlic, onions or macadamia nuts. Each contains a compound that causes specific harm in dogs, from kidney failure to seizures.
Chocolate contains theobromine and caffeine, both methylxanthines that dogs metabolize slowly. The Merck Veterinary Manual documents theobromine toxicity in dogs, with progressively severe effects as the dose increases. Dark chocolate and baking chocolate contain far more theobromine than milk chocolate. Cornell University states that as little as 0.1 ounce of baking chocolate per pound of body weight may be lethal.
Grapes and raisins cause acute kidney failure in dogs. A 2024 scoping review in Veterinary Record identified tartaric acid as the likely toxic compound, ending decades of uncertainty about the mechanism. Individual dogs vary widely in sensitivity, and Cornell University states that no safe threshold has been established. Any ingestion should be handled as potentially serious.
Xylitol is an artificial sweetener found in sugar-free gum, baked goods, peanut butter and other products. In dogs, xylitol triggers a rapid insulin release that causes hypoglycemia. A 2015 retrospective study of 192 dogs documented hypoglycemia and liver injury following xylitol ingestion. The Merck Veterinary Manual notes that xylitol does not affect cats.
Garlic and onions both damage red blood cells in dogs, leading to hemolytic anemia. The Merck Veterinary Manual states that garlic is three to five times more toxic than onions on a weight basis. A 2026 case report in Animals documented a fatal case in which a dog ate approximately 40 grams of raw garlic.
Macadamia nuts cause temporary weakness, tremors and elevated body temperature in dogs, though the toxic compound has not been identified. A 2004 study by ASPCA Poison Control induced clinical signs in four dogs and reviewed 48 retrospective cases. Symptoms usually appear within 12 hours and most dogs recover within 24 to 48 hours.
How much of a toxic food causes harm in dogs?
Toxic thresholds vary by food and by the individual dog.
For xylitol, the 2015 study of 192 dogs documented hypoglycemia in dogs that ingested xylitol, with liver injury observed at higher exposures. Even small ingestions can be dangerous for small dogs, because a single piece of sugar-free gum may contain hundreds of milligrams of xylitol.
For chocolate, the Merck Veterinary Manual provides theobromine thresholds and describes mild signs at lower doses, cardiotoxic effects at intermediate doses, and seizures at higher doses. Baking chocolate contains far more theobromine than milk chocolate, so a small amount carries significant risk.
For grapes and raisins, no safe threshold exists. One study cited by the Merck Veterinary Manual showed toxicity at certain doses, but individual sensitivity varies so widely that Cornell advises handling any ingestion as serious.
For garlic, the 2026 Animals case report documented a fatal case involving approximately 40 grams of raw garlic. For onions, the Merck Veterinary Manual states that toxicity can occur when onions make up approximately 0.5 percent of body weight. Symptoms may not appear for several days.
For macadamia nuts, the Merck Veterinary Manual describes temporary weakness and tremors following ingestion.
What are the symptoms of food poisoning in dogs?
Symptoms depend on the toxic food.
Chocolate poisoning causes vomiting, diarrhea, restlessness, increased urination, tremors, elevated heart rate, arrhythmias and seizures. Signs appear within 6 to 12 hours of ingestion.
Xylitol poisoning causes vomiting, weakness, lethargy, collapse, seizures and loss of coordination. Hypoglycemia signs appear within 30 minutes to an hour. Liver injury signs, if they occur, develop within 12 to 24 hours.
Grape or raisin poisoning causes vomiting, lethargy, loss of appetite, abdominal pain, decreased urination and dehydration. Symptoms typically appear within 12 to 24 hours. Kidney failure develops over the following days.
Garlic and onion poisoning causes weakness, lethargy, pale gums, red or brown urine, vomiting, diarrhea and elevated heart rate. Red blood cell damage accumulates, so symptoms may not appear for several days after ingestion.
Macadamia nut poisoning causes hind limb weakness, inability to stand, tremors, vomiting, elevated body temperature and joint pain. Signs usually appear within 12 hours and resolve within 24 to 48 hours.
What should I do if my dog eats a toxic food?
Call your veterinarian immediately, or contact the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661. Both lines are available 24 hours a day.
Have the following information ready: what your dog ate, how much, when it happened, and your dog's weight. If the product has a label, keep it on hand.
Do not induce vomiting unless your veterinarian tells you to. For some toxins, vomiting helps. For others, it can make things worse or cause aspiration.
Time matters. For xylitol, chocolate and grapes, early intervention is most successful. Your vet may induce vomiting, administer activated charcoal to limit absorption, provide intravenous fluids, monitor blood sugar and organ function, and give supportive care.
For xylitol ingestion, Cornell University recommends decontamination within one to two hours if the dog has not yet vomited, followed by blood glucose monitoring every one to two hours for at least 12 hours, and liver enzyme monitoring for 48 to 72 hours.
Is avocado safe for dogs?
Avocado flesh poses minimal toxicity risk to dogs. Dogs are relatively resistant to persin, the compound in avocado that is toxic to birds, horses, rabbits and ruminants, according to the Merck Veterinary Manual.
The primary dangers are the pit and the fat content. The pit can cause intestinal obstruction if swallowed. The flesh is high in fat and may trigger pancreatitis in dogs prone to the condition.
If your dog eats a small amount of avocado flesh, monitor for stomach upset such as vomiting or diarrhea. If your dog swallows the pit or shows signs of abdominal pain, straining, vomiting or lethargy, see your vet immediately.
Can dogs eat blueberries or strawberries?
Yes. Blueberries and strawberries are safe for dogs and provide fiber and vitamin C.
A 2017 randomized controlled trial in the Journal of Nutritional Science tested a blueberry and grape extract supplement in 35 aged beagle dogs. The study found improved performance on working memory tasks after 12 weeks. A 2025 feeding trial found that dogs tolerated blueberries well and showed no negative effects on digestibility or oxidative balance after exercise.
Serve fresh or frozen berries in small amounts as an occasional snack. Wash them first. Too much of any fruit can cause stomach upset.
What other foods should I ask my vet about?
Ask your vet before introducing any new food to your dog's diet, especially if your dog has a health condition, takes medication, or has had a reaction to a food in the past.
Common questions include foods high in fat, which may trigger pancreatitis, and foods that are choking hazards or that may cause obstruction. Your vet can guide you based on your dog's size, age, health and individual sensitivities.
If your dog shows vomiting, diarrhea, lethargy, loss of appetite, abdominal pain or any other sign of illness after eating something new, contact your vet right away.
