What foods are toxic to dogs?

As a veterinarian who has treated dozens of accidental ingestions, I write with practical urgency: knowing which human foods are dangerous and how to respond can mean the difference between a short clinic visit and an emergency that threatens your dog’s life. This guide is organized to help you act quickly and prevent problems before they happen.

How toxic foods can impact your dog’s health — and why it matters

Dogs are curious and fast-moving around anything that smells like food. In a kitchen where you’re cooking, during a party with guests passing plates, on holiday tables with rich dishes, or when garbage is left accessible, a single greedy mouthful can be hazardous. I typically see incidents after holiday dinners and when guests drop food or offer “just a bite.”

Owners generally want three things: to prevent exposure, to recognize trouble early, and to act in ways that maximize a good outcome. That means learning which items to lock away, noticing subtle changes in behavior, and knowing who to call when you’re unsure.

Certain dogs are more vulnerable. Puppies and small breeds are at higher risk because a small amount of a toxin becomes a large dose relative to body weight. Senior dogs may have weaker livers or kidneys and tolerate toxins less well. Brachycephalic breeds (those flat-faced dogs) can have a bit more trouble clearing their airways if they vomit and may decompensate faster from respiratory stress; I often advise tighter supervision for those pets during gatherings.

At a glance: common human foods that can poison dogs

• Chocolate: Theobromine and caffeine in chocolate are among the highest-risk items. Dark and baking chocolate contain more toxin per ounce and may cause vomiting, hyperactivity, tremors, rapid heart rate and seizures depending on the dose.
• Xylitol: This artificial sweetener (often in sugar-free gum, candy, some peanut butters and baked goods) may trigger rapid insulin release in dogs, leading to severe hypoglycemia; liver injury is also possible after larger exposures.
• Grapes and raisins: Even small amounts may be linked to sudden kidney failure in some dogs; sensitivity seems variable but the risk is serious enough to treat any ingestion as potentially dangerous.
• Onions and garlic: These can cause oxidative damage to red blood cells, producing anemia over days; powdered and concentrated forms may be worse than cooked pieces.
• Macadamia nuts: Typically cause transient weakness, tremors and temperature increases; the exact toxin is unknown but clinical signs usually appear within hours.
• Alcohol and caffeine: Both depress or overstimulate the nervous system. Alcohol can cause disorientation and low blood sugar; caffeine leads to agitation, fast heart rate and tremors.
• Yeast dough: Rising dough can expand in the stomach and produce ethanol as it ferments, causing both physical obstruction and intoxication.
• Variable-risk items: Avocado (persin in some species may be an issue), certain nuts (like walnuts which can be contaminated with mold), and high-fat foods or cooked bones that can cause pancreatitis or GI obstruction—these are risky depending on amount and the individual dog.

What happens inside a dog after eating toxic foods

Different foods act through different biological pathways. Theobromine and caffeine are stimulants that interfere with cardiac and nervous system ion channels and promote excessive sympathetic activity; that is likely linked to elevated heart rate, tremors, and seizures. Xylitol stimulates a rapid release of insulin in dogs, which may cause an acute drop in blood sugar and subsequent weakness or collapse; it is also associated with liver cell injury in some cases.

Grapes and raisins are associated with acute kidney injury; the exact compound responsible remains unclear, but the pattern is consistent: an apparently healthy dog may develop vomiting and reduced urine output within 24–72 hours and progress to signs of renal compromise. Onions and garlic contain sulfur compounds that may cause oxidative damage to red blood cells, producing hemolytic anemia that can be delayed by several days after exposure.

Dose matters. Toxicity is typically dose-dependent relative to body weight: the same amount of chocolate that causes mild signs in a 60 kg dog may be life-threatening for a 5 kg terrier. Some toxicities (grapes, xylitol) can occur at surprisingly low doses in susceptible individuals, which is why conservative action is usually best.

When dogs are most at risk — situations, timing, and vulnerable pets

Many poisonings are predictable by context. Open counters, grocery bags on the floor, accessible trash, and guests who hand-feed are common exposures. I often emphasize the role of human behavior: leaving unattended plates at dog level during barbecues, or assuming “just one bite” is harmless, sets the stage for trouble.

Life stage and breed matter. Puppies explore with their mouths and are more likely to ingest a broad range of foods, while senior dogs with reduced hepatic or renal reserve may show severe effects from smaller doses. Small breeds are at higher relative risk because a tiny absolute amount can be a large mg/kg dose. Brachycephalic breeds may not tolerate stressors like vomiting or seizures as well.

Temporal triggers include holidays, parties, and walks where dogs might find fallen fruit or discarded food wrappers. I recommend heightened vigilance during these times and making a brief risk checklist before gatherings: secure counters, stow toxic foods, and designate a place for the dog away from high-traffic food areas.

Spotting the first signs: what to watch for after ingestion

• Gastrointestinal signs (usually the first to appear): vomiting, diarrhea, drooling, and decreased appetite. These often show within minutes to a few hours of ingestion depending on the food.
• Neurologic and cardiac signs: tremors, wobbliness, unusual staring, muscle rigidity, seizures, fast or irregular heartbeat. These can occur within a few hours for stimulants like caffeine or chocolate and may progress quickly.
• Delayed or subtle signs: lethargy, pale gums, rapid breathing, jaundice, increased drinking or urination. Hemolytic anemia from onions or liver injury from xylitol may have delayed onset; renal signs from grapes/raisins may not peak until 24–72 hours after ingestion.

Immediate steps to take if your dog eats something poisonous

First, stay calm and try to establish three things: what was eaten, approximately how much, and when. If you can safely do so, gather packaging or take a photo of the product and the dog’s mouth/behavior to show your veterinarian. This information greatly improves triage and treatment decisions.

Contact your veterinarian or a poison control service immediately; many of these centers operate 24/7 and will ask the same key details. I generally advise against attempting home remedies like inducing vomiting or giving activated charcoal unless a veterinarian instructs you to do so—some substances make vomiting hazardous, and timing matters.

If the dog is having seizures, is unconscious, or is having trouble breathing, get to an emergency clinic right away. If instructed to induce vomiting at home, use only the method your veterinarian recommends and watch for aspiration in brachycephalic breeds. Transport with safety: use a leash or crate to keep the dog secure and prevent further injury during movement.

Preventing incidents at home: storage, training, and safer alternatives

Prevention combines environmental changes and consistent training. Store human foods in high cabinets or closed containers rather than on counters. Make a habit of sweeping up crumbs promptly and keeping grocery bags and takeout containers out of reach.

Train reliable cues such as “leave it” and “drop.” Start training in low-distraction environments and gradually add temptations so the dog learns to respond even when food is present. Supervised feeding protocols—feeding the dog at a set station while people eat—reduce the chance that a guest will slip a dangerous bite.

Set clear visitor rules. Ask guests not to offer table scraps and point out offensive items politely. If someone insists on sharing, have a small batch of vet-approved treats available so the dog gets attention without risk.

Essential tools and safety gear every dog owner should keep on hand

Physical barriers are straightforward and effective. Childproof cabinet locks and high, opaque storage containers make counter access less likely. Trash cans with locking lids, heavy bases, or tuck-away trash closets reduce rummaging. I often recommend sealed bins rather than flimsy liners that pets can tear open.

A basic pet first-aid kit is useful: include gloves, digital thermometer, a leash, saline for eye rinsing, a copy of your dog’s medical history, and emergency contact numbers. Place an emergency contact card on the fridge with your vet and the number for a poison helpline so anyone in the household can act quickly.

Finally, a sturdy leash and a crate make rapid control easier if a dog bolts after a dropped item or if you need to transport them quickly to the clinic.

Who to contact: your vet, animal poison control, and trusted authorities

When in doubt, consult professionals. Your primary-care veterinarian is the first point of contact for most exposures. Emergency veterinary clinics are equipped for urgent care, and veterinary toxicologists or specialists can be consulted for complex cases.

National poison resources provide up-to-date, veterinarian-reviewed guidance and often operate 24/7. Keep the phone numbers for them handy; these services can triage risk and recommend immediate steps before you reach a clinic.

References and further reading — the evidence behind these recommendations

• ASPCA Animal Poison Control Center: “Foods That Are Toxic to Pets” (https://www.aspca.org/pet-care/animal-poison-control)
• Pet Poison Helpline: “Foods Toxic to Dogs” (https://www.petpoisonhelpline.com/pet-poison-control/poison-index/food/)
• Merck Veterinary Manual: “Chocolate (Theobromine) Toxicity” (https://www.merckvetmanual.com/toxicology/chocolate-theobromine-toxicity)
• American Veterinary Medical Association (AVMA): “Pet Poisoning” resources and guidance for household toxins (https://www.avma.org/resources-tools/pet-owners/petcare/pet-poisoning)
• Gwaltney-Brant, S. “Grapes and Raisins: A Potentially Toxic Food for Dogs.” Journal of the American Veterinary Medical Association (JAVMA), case review and clinical guidance on acute renal failure linked to grape ingestion.