When a dog eats table scraps, the outcome ranges from nothing at all to a life-threatening emergency, depending entirely on what was in the food, how much the dog ate, and the dog’s size. A plain piece of chicken off your plate is unlikely to cause harm. A slice of chocolate cake or a dish seasoned with onions and garlic is a different story. Here’s what actually happens inside your dog’s body when human food goes down.
The Most Common Reaction: Stomach Upset
The single most frequent outcome of eating table scraps is acute gastroenteritis, which is exactly what it sounds like: inflammation of the stomach and intestines. Veterinarians call this “dietary indiscretion,” and it typically causes a sudden onset of vomiting, diarrhea, and loss of appetite. Rich, greasy, or heavily seasoned foods are the usual culprits. Your dog’s digestive system is adapted to a consistent diet, so even non-toxic foods can cause trouble simply because they’re unfamiliar.
Some foods trigger osmotic diarrhea, where undigested material pulls water into the intestines. This is why a dog who raids a plate of buttery mashed potatoes might have watery stool for a day or two. Most cases of dietary indiscretion resolve on their own within 24 to 48 hours, but puppies, senior dogs, and small breeds can dehydrate quickly.
Fatty Foods and Pancreatitis
High-fat table scraps pose a specific and serious risk: pancreatitis. When a dog eats a large amount of fatty food (think bacon grease, ham, fried anything, or buttery dishes), the flood of triglycerides into the bloodstream overwhelms normal fat processing. Enzymes that normally break down fat inside the intestines start generating excess free fatty acids in the blood, which damage the pancreas itself. The damaged pancreas then leaks even more of its own fat-digesting enzymes, creating a destructive cycle that worsens the inflammation.
Pancreatitis can be mild or severe. Mild cases cause vomiting, abdominal pain, and lethargy that resolve with veterinary care over a few days. Severe cases can lead to organ failure and death. Some breeds, including Miniature Schnauzers and Cocker Spaniels, are especially prone. A single fatty meal is enough to trigger an episode, particularly around holidays when dogs get access to turkey skin, gravy, or ham trimmings.
Foods That Are Genuinely Toxic
Several common ingredients in human meals are poisonous to dogs. These aren’t just “bad for them” in a vague sense. They cause specific organ damage.
- Onions, garlic, and chives damage red blood cells, leading to anemia. Onions are toxic at roughly 15 to 30 grams per kilogram of body weight, meaning a 20-pound dog could be harmed by eating less than half a medium onion. Garlic is toxic at similar concentrations by weight. Cooked, raw, and powdered forms all count, so soups, sauces, and seasoned meats are common sources of exposure.
- Grapes and raisins can cause kidney damage. The suspected toxic component is tartaric acid, which dogs cannot process. There’s no established safe dose, and some dogs are affected by just a few grapes while others seem unharmed. Raisins are more concentrated and therefore more dangerous gram for gram.
- Chocolate contains compounds called methylxanthines that cause vomiting, diarrhea, rapid heart rate, tremors, seizures, and potentially death. Baking chocolate and cocoa powder have the highest concentrations. White chocolate has very little and is far less dangerous, though still not safe.
- Xylitol (birch sugar) is one of the most dangerous substances a dog can encounter in human food. It triggers a rapid, severe drop in blood sugar that can cause vomiting, loss of coordination, and seizures. Liver damage can follow within 12 to 24 hours. Xylitol shows up in sugar-free gum, mints, some peanut butters, baked goods, sugar-free ice cream, and even children’s chewable vitamins. Always check labels on any “sugar-free” product before sharing it with a dog.
- Macadamia nuts cause weakness, vomiting, tremors, and overheating. The exact mechanism isn’t fully understood, but symptoms typically appear within 12 hours of ingestion.
Salt and Processed Foods
Processed human foods (deli meats, chips, canned soups, pizza) contain far more sodium than a dog needs. Dogs show signs of salt toxicity after ingesting about 2 to 3 grams of salt per kilogram of body weight, and the lethal dose is around 4 grams per kilogram. For a 10-pound dog, that’s roughly 18 grams of salt, which sounds like a lot until you consider that a single cup of canned soup can contain over 2 grams of sodium.
Salt toxicity causes excessive thirst, vomiting, diarrhea, tremors, and in severe cases, seizures. Small dogs are at the highest risk because the threshold is reached with a much smaller amount of food.
Weight Gain and Shortened Lifespan
The most overlooked consequence of table scraps is the one that happens gradually. Veterinary guidelines recommend that no more than 10% of a dog’s daily calories come from treats or non-balanced foods. That ceiling is easy to hit. A tablespoon of peanut butter is about 100 calories, which could represent a quarter of a small dog’s daily needs.
A large study published in the Journal of Veterinary Internal Medicine found that overweight dogs consistently lived shorter lives than dogs at a healthy weight, across every breed studied. The difference ranged from 5 months for German Shepherds to 2 years and 6 months for Yorkshire Terriers. Overweight Yorkshire Terriers had a median lifespan of 13.7 years compared to 16.2 years for normal-weight dogs of the same breed. That’s a meaningful chunk of time lost to extra calories.
Table scraps also displace balanced nutrition. A dog who fills up on chicken skin and bread crusts is getting calories without the vitamins, minerals, and balanced macronutrients in their regular food. Over months and years, this creates nutritional gaps even in dogs who aren’t obviously overweight.
Begging and Behavior Problems
Every time a dog receives food from the table, it reinforces the behavior that got them the food. You’re teaching your dog that staring, whining, or pawing at you during meals works. This is straightforward operant conditioning, and dogs learn it fast. Once established, begging is difficult to extinguish because even occasional rewards (one person at the table giving in) keep the behavior alive.
Begging can also escalate. Dogs who learn that human mealtimes produce food may progress to counter-surfing, stealing food off plates, or becoming pushy and demanding around anyone who’s eating. If you want to share safe human foods with your dog, the better approach is placing them in the dog’s bowl away from the table, ideally as a reward for calm behavior like lying on a designated mat.
Scraps That Are Actually Fine
Not all human food is dangerous. Plenty of table-friendly options are safe in moderation, as long as they’re plain, unseasoned, and served in small portions that stay within that 10% calorie guideline.
- Lean proteins: Plain cooked chicken, turkey (without skin or excess fat), fully cooked eggs, and cooked fish like salmon or sardines are all excellent protein sources. Cooked shrimp is safe with shells removed. Pork is fine if it’s lean and unseasoned.
- Vegetables: Carrots, green beans, cucumber, and plain cooked sweet potato are low-calorie options most dogs tolerate well.
- Peanut butter: A good source of protein and healthy fats, but only the unsalted, xylitol-free kind. Always read the ingredients.
- Plain yogurt: Skip flavored or sweetened versions, but plain yogurt is generally safe and well tolerated.
The key distinction is between intentionally sharing a small amount of known-safe food and letting a dog eat whatever falls off the table or licking a plate clean. The first can be part of a healthy relationship with your dog. The second is where stomach upsets, toxic exposures, and creeping weight gain come from.