The Human Foods That Actually Poison Dogs

Most kitchen scraps do nothing worse than upset a stomach. A short list is genuinely dangerous, and for those the useful thing to know is not that they are bad but roughly how much matters, because that helps the veterinary team assess the exposure when you call promptly.

Everything below comes from veterinary toxicology references. None of it replaces a phone call: the dose, the dog and the timing all change the answer.

Key figures

• 10 to 60 minutes Possible xylitol blood-sugar crash onset
• 0.1 g per kg Xylitol dose linked to low blood sugar
• 0.5 g per kg Xylitol dose linked to liver failure

Xylitol, the one most people underestimate

Xylitol is a sugar alcohol used in sugar-free gum, mints, some peanut butters, baked goods and toothpaste. The FDA warns that in dogs it triggers a potent release of insulin, and that blood sugar can crash within 10 to 60 minutes of eating it.

The Merck Veterinary Manual gives the thresholds:

• Over 0.1 g per kg of body weight: risk of hypoglycemia.
• Over 0.5 g per kg: risk of acute liver failure.

For a 10 kg dog that is 1 gram of xylitol for the first threshold, which a few pieces of gum can contain. Merck also notes signs of liver injury may not appear for 24 to 48 hours, so a dog that looks fine is not evidence that nothing happened.

Chocolate: the type matters more than the amount

The toxic compounds are methylxanthines, mainly theobromine. Merck gives these concentrations:

And these effect thresholds: mild signs from 20 mg/kg, cardiotoxic effects at 40 to 50 mg/kg, and seizures at 60 mg/kg or more.

Milk chocolate can also cause serious effects; contact a veterinarian or pet poison service after suspected exposure. The same dog eating baking chocolate is a very different call, and a small dog changes the arithmetic again.

Grapes and raisins

The toxic component is now thought to be tartaric acid, which dogs excrete poorly. Merck’s guidance is that more than one grape or raisin per 4.5 kg, about 10 pounds, of body weight may contain enough to risk kidney injury, and that affected dogs generally develop kidney failure within 72 hours.

Raisins concentrate the problem into a much smaller volume, which is why a handful of trail mix or a slice of fruit cake is worth a phone call.

The rest of the short list

• Onions, garlic, leeks and chives. Damage red blood cells. Cooked, raw and powdered all count, and powdered forms are concentrated. The anaemia can take days to appear.
• Macadamia nuts. Cause weakness, tremors and hind limb problems, usually temporary but alarming.
• Alcohol, including raw yeast dough, which ferments in the stomach and also expands.
• Cooked bones. Not a poison but a common cause of fractured teeth, obstructions and perforations.

What to do when something has been eaten

1. Work out what and how much, and the dog’s weight. Keep the packaging.
2. Phone before symptoms start. Prompt advice matters; there is no universal safe waiting window.
3. Do not induce vomiting on your own initiative. For some substances it makes things worse, and the decision belongs to the person on the phone.
4. Save the number. Your vet, your nearest 24-hour clinic, and a pet poison control line. Poison lines charge a consultation fee and are worth it.

The dog food label guide addresses routine nutrition separately from exposure risks. The diagnostic estimate guide explains costs without postponing urgent assessment.

Questions people ask

How much chocolate is dangerous for a dog?

It depends on the type and the dog's weight. Mild signs start around 20 mg of methylxanthines per kg, and baking chocolate contains roughly seven times as much per ounce as milk chocolate.

My dog ate one grape. Should I worry?

Merck's guidance is that more than one grape or raisin per 10 pounds of body weight may be enough to risk kidney injury. For a small dog, one grape is worth a call. Call promptly after any known grape or raisin exposure; the count is not a safe cutoff.

What if my dog ate sugar-free gum?

Treat it as an emergency and call immediately. Xylitol can drop blood sugar within 10 to 60 minutes, and the amount in a few pieces can exceed the threshold for a small dog.

Is peanut butter safe for dogs?

Plain peanut butter is fine. Some sugar-free versions contain xylitol, so check the ingredient list on the specific jar before using it for treats or medication.

Where these figures come from

1. Paws Off Xylitol; It is Dangerous for Dogs US Food and Drug Administration · fda.gov
2. Xylitol Toxicosis in Dogs Merck Veterinary Manual · merckvetmanual.com
3. Chocolate Toxicosis in Animals Merck Veterinary Manual · merckvetmanual.com
4. Grape, Raisin, and Tamarind Toxicosis in Dogs Merck Veterinary Manual · merckvetmanual.com

Figures last checked September 2026.