Dogs will eat almost anything, which makes it our responsibility to know what “almost anything” includes that could hurt them. The list of toxic foods is longer than most dog owners realize, and some items on it will surprise you — a handful of grapes or a single sugar-free piece of gum can be fatal for a medium-sized dog.
Xylitol — The Hidden Killer
Xylitol is an artificial sweetener found in sugar-free gum, some peanut butters, candy, mouthwash, vitamins, and hundreds of other products. In dogs, it triggers a massive insulin release that causes life-threatening hypoglycemia (blood sugar crash) within 30–60 minutes. Higher doses cause acute liver failure.
Toxic dose: As little as 0.1g/kg body weight for hypoglycemia; liver failure begins around 0.5g/kg. A single piece of sugar-free gum typically contains 0.2–0.4g of xylitol. For a 10-lb dog, this is potentially fatal.
Always check the ingredients in peanut butter before giving it to your dog. Several popular brands have switched to xylitol-containing formulas.
Grapes and Raisins
Grapes, raisins, currants, and sultanas can cause acute kidney failure in dogs. The exact toxic compound has not been identified, which means there is no established “safe” dose. Some dogs have eaten large quantities without apparent harm; others have developed kidney failure from a small amount. The safest approach: treat all grapes and grape products as completely off-limits.
Raisins are even more dangerous due to their concentration. A single small box of raisins can be enough to cause kidney failure in a medium-sized dog.
Chocolate
Chocolate contains theobromine and caffeine, both of which dogs metabolize far more slowly than humans. The result is overstimulation of the central nervous system and cardiovascular system. Symptoms include vomiting, diarrhea, rapid breathing, muscle tremors, and seizures.
Toxicity depends on the type of chocolate and the dog’s size. Dark chocolate and baking chocolate are the most dangerous — they contain 10 times more theobromine than milk chocolate. White chocolate contains negligible theobromine but still presents a fat and sugar risk. Our Dog Toxicity Calculator can calculate whether a specific amount your dog ate crosses the dangerous threshold for their weight.
Onions, Garlic, Leeks, and Chives
All members of the Allium family damage red blood cells in dogs, causing hemolytic anemia — a breakdown of the red blood cells that leads to weakness, pale gums, and in severe cases, organ failure. Cats are even more sensitive than dogs, but the risk in dogs is significant especially with repeated exposure.
Cooked and powdered forms are more toxic than raw by weight. This makes garlic powder and onion powder in prepared foods particularly dangerous — a small amount seasoning can contain a high concentration. Baby food with onion powder has caused toxicity in dogs.
Macadamia Nuts
Macadamia nuts cause weakness, hyperthermia (elevated body temperature), vomiting, tremors, and depression in dogs. The mechanism is unknown. Symptoms typically begin within 12 hours of ingestion. While rarely fatal on their own, macadamia nuts combined with chocolate (as in chocolate-covered macadamias) create a significantly elevated risk.
Alcohol and Raw Yeast Dough
Alcohol causes the same effects in dogs as in humans — disorientation, vomiting, low blood pressure, low blood sugar — but at a fraction of the dose. A small amount of beer, wine, or spirits can cause alcohol poisoning in a small dog.
Raw yeast dough presents two risks: the yeast ferments in the warm, moist stomach environment producing alcohol (ethanol toxicity), and the expanding dough causes painful gastric distension that can lead to bloat. Both are emergencies.
Foods Commonly Misunderstood
Cooked chicken bones: Dangerous. Cooking makes bones brittle, causing them to splinter into sharp fragments that can perforate the esophagus, stomach, or intestines. Raw bones are generally safer but still carry a risk of obstruction and bacterial contamination.
Avocado: The flesh in small amounts is generally considered low-risk for dogs (the concern is mainly in birds and other animals). However, avocado pits are a serious choking and obstruction hazard, and the skin contains persin which is toxic to many species. Best to avoid entirely.
Salt: High-salt foods can cause sodium ion poisoning. A dog eating a large quantity of salted chips or pretzels in one sitting is at risk of vomiting, diarrhea, tremors, and seizures.
Nutmeg: In quantities found in baked goods, nutmeg poses minimal risk. In large amounts, it causes tremors, seizures, and death. Keep away from the spice cabinet.
What to Do If Your Dog Eats Something Toxic
- Stay calm. Your dog can sense your panic, and you need to be thinking clearly.
- Note the time, what the dog ate, and approximately how much.
- Call ASPCA Poison Control: (888) 426-4435 (there is a consultation fee) or your veterinarian.
- Do not induce vomiting unless specifically instructed to by a vet or poison control. Some substances cause more damage coming back up.
- If instructed to go to a vet, bring the packaging or a photo of the label.
Use Our Free Dog Toxicity Calculator
Our Dog Toxicity Calculator covers 20+ substances including all chocolate types, grapes, xylitol, onions, common medications, and household chemicals. Enter the substance and your dog’s weight for an instant assessment of toxicity risk, expected symptom timeline, and guidance on how quickly to seek care.