Foods That Are Toxic to Dogs and Cats: A Reference Guide

Why Some Human Foods Are Dangerous to Pets

Dogs and cats have metabolic systems that differ significantly from humans. Compounds that the human liver processes without issue can accumulate to toxic levels in pets, trigger organ failure, or interfere with red blood cell function. Understanding why a food is harmful — not just that it is — helps owners take the risk seriously and act quickly if an exposure occurs.

This reference covers the most commonly reported toxic foods for dogs and cats based on data from veterinary toxicology resources, including the ASPCA Animal Poison Control Center. If you suspect your pet has ingested any of the items listed here, contact your veterinarian or an animal poison control hotline immediately. Do not wait for symptoms to appear.

For a broader look at keeping your home safe, see the room-by-room pet safety checklist that covers kitchen hazards alongside other household risks.

The Most Harmful Foods: What They Are and Why They Cause Harm

The foods below represent the highest-risk items for household pets. Toxicity can depend on the amount ingested, the size of the animal, and individual sensitivity — but no safe threshold has been established for many of these, so all exposure should be treated as a concern.

• Xylitol (birch sugar): Found in sugar-free gum, some peanut butters, baked goods, and dental products. In dogs, xylitol triggers a rapid release of insulin, causing dangerous hypoglycemia (low blood sugar). Higher doses can cause acute liver failure. Cats appear less commonly exposed but are also considered at risk.
• Grapes and raisins: The toxic mechanism in grapes and raisins is not fully identified, but both are linked to acute kidney failure in dogs. Even small amounts have caused serious illness in some individuals. Raisins are more concentrated and considered higher risk per gram.
• Onions, garlic, leeks, and chives: All members of the Allium family contain compounds called thiosulfates that damage red blood cells in both dogs and cats, leading to hemolytic anemia. Cats are more sensitive than dogs. Cooked forms are just as dangerous as raw.
• Chocolate and caffeine: Chocolate contains theobromine and caffeine, both of which dogs and cats metabolize very slowly. Dark chocolate and baking chocolate have the highest theobromine concentrations. Effects include vomiting, tremors, elevated heart rate, and in severe cases, seizures.
• Macadamia nuts: Toxic to dogs; the mechanism is unknown. Signs include weakness, hyperthermia, vomiting, and tremors, typically within 12 hours of ingestion. Cats are not well studied but should be kept away as a precaution.
• Avocado: Contains persin, a fungicidal toxin found in the flesh, skin, pit, and leaves. Birds and small mammals are highly susceptible. In dogs and cats, the primary concern is gastrointestinal upset; the pit also poses a choking and obstruction hazard.
• Alcohol: Even small amounts of ethanol can cause vomiting, disorientation, respiratory depression, and dangerously low blood sugar in pets. Fermented foods such as raw dough can also produce alcohol as yeast metabolizes in the stomach.
• Raw yeast dough: Expands in the warm stomach environment, causing painful bloating and potentially life-threatening gastric dilation. Fermenting yeast also produces ethanol, compounding the toxic risk.
• Cooked bones: While not a food toxin in the chemical sense, cooked bones splinter and can cause internal lacerations, obstructions, or choking. This is an important safety note for owners who prepare meat at home.

If you are preparing homemade meals for your pet, reviewing commonly overlooked nutrients in homemade pet diets can help you build a safer, more complete diet overall.

This article is for general informational purposes only and is not a substitute for veterinary advice. If your pet has ingested a potentially toxic substance, contact your veterinarian or the ASPCA Animal Poison Control Center immediately.