10 Foods That Are Dangerous for Your Dog

Analysis by Dr. Karen Shaw Becker

toxic foods for dogs

Story at-a-glance -

  • Tis the season for overindulging, and a good time to remember that several foods that are safe for humans are toxic to dogs
  • A few of the foods you’ll want to keep safely away from your pet include anything containing the sweetener xylitol, chocolate in any form, grapes and raisins, macadamia nuts, and cooked bones

This time of year, all kinds of tasty temptations find their way into our cupboards, pantries, and refrigerators, and onto our kitchen counters and tables. Given that everyone seems to overindulge during the holiday season, including canine family members if given the chance, it’s a good time for a reminder that several foods that are fine for humans to eat can be toxic to dogs.

10 Foods That Can Be Toxic for Your Dog

1. Xylitol — Xylitol is a natural sweetener that is highly toxic to dogs, and it’s being found in an ever-growing list of consumer products because it’s as sweet as sucrose, but with only two-thirds the calories of sugar. It’s less expensive than other sugar substitutes, in some cases tastes better, and causes little if any insulin release in humans.

Just a few years ago, xylitol could be found in less than a hundred products in the U.S. Today it can be found in a wide range of health and beauty products, food products, over-the-counter drugs and supplements, and prescription medications. Dr. Ahna Brutlag, associate director of veterinary services for Pet Poison Helpline explains the seriousness of the situation:

“First, dogs fed straight peanut butter as a treat or fed treats baked with xylitol-containing peanut butter may certainly be at risk for harm. Second, a dog that nabs the entire jar of xylitol-containing peanut butter and happily gorges on his or her treasure without anyone knowing could quickly become extremely ill.

If this occurred during the day while the owners were not home, it’s possible the dog could die before people returned.”1

You should be aware of any product in your home containing xylitol, and especially anything you might consider offering to your dog. You can find a comprehensive list of products containing xylitol here.

2. Caffeine — Most people are aware that chocolate is toxic to dogs. Chocolate contains substances known as methylxanthines, which include not only theobromine but also caffeine. Both theobromine and caffeine stimulate the central nervous system and heart muscle. They also relax smooth muscles, especially the bronchial muscles, and increase production of urine by the kidneys.

If your dog manages to sneak a sip or two of your coffee in the morning, it’s unlikely to make him sick. However, the consumption of coffee grounds, black or green tea bags or caffeine-containing diet pills or painkillers (even just one or two) could be deadly in small dogs. Depending on the amount ingested, symptoms may be mild, such as slight restlessness and minimally elevated heart rate, to deadly.

If you suspect your dog may have consumed something with caffeine, seek emergency veterinary care immediately. Vomiting may be induced and activated charcoal may be given to help with decontamination. Supportive care (e.g., intravenous fluids and medications to stabilize heart rate and blood pressure) may also be required depending on your pet’s symptoms.

3. Chocolate — Chocolate is made from the roasted seeds of the Theobroma cacao or cocoa tree. The seeds have certain properties that can be toxic for dogs, including caffeine and theobromine (see above), which are naturally occurring stimulants. Studies show dogs are especially sensitive to theobromine compared to other domestic animals. This is because they metabolize the substance very slowly, which means it stays in the bloodstream for an unusually long time.

Even small amounts of chocolate can cause adverse reactions in pets, and the darker the chocolate, the more theobromine it contains. Baker’s chocolate, semisweet chocolate, cocoa powder, and gourmet dark chocolates are more dangerous than milk chocolate. Other sources include chewable flavored multivitamins, baked goods, chocolate-covered espresso beans, and cocoa bean mulch.

Though not commonly seen, the worst of the worst is dry cocoa powder, which contains the highest amount of theobromine per ounce — 800 milligrams per ounce versus Baker’s chocolate at 450 milligrams per ounce.

4. Onions and other plants containing allium — Plants of the genus allium, which includes onions, chives, garlic, and leeks, make some pets sick (there have even been fatalities), while others don’t seem affected. Symptoms of allium poisoning can occur a day or several days after ingestion, depending on the amount eaten.

The toxic compounds in allium plants are organosulfoxides. When chewed, organosulfoxides convert to a mixture of sulfur compounds that can damage your dog’s red blood cells. According to LiveScience:

“If [a] dog or cat ingests even just a piece of an onion (specifically, 5 grams of onion per kilogram of body weight for cats, or 15 to 30 grams per kg for dogs), it can cause dangerous changes to their blood.”2

Garlic can cause changes in blood parameters when fed in excessive quantities (much more than pets would naturally eat) or if it is given in a garlic supplement (which I never recommend). Dogs can healthfully consume ¼ teaspoon of freshly chopped garlic per 15 pounds of body weight and reap substantial health benefits, just don’t go overboard. 

5. Grapes and raisins — In 2016, I interviewed Melissa Gardner, an intelligence specialist with the FBI and a former military intelligence officer, who offered a very interesting and plausible theory to explain why grapes and raisins, once safe to feed pets, are now toxic. She believes that fluoride-based pesticides used on grapevines could be to blame.

According to studies, grapes, raisins, sultanas, and currants – both raw and cooked – can cause kidney failure in dogs. However, not all dogs have the same reaction to these foods. For example, one study examined 180 cases of dogs who ate grapes and related fruits and reported that some dogs showed no symptoms after eating 2 pounds of raisins, while others died after eating just a handful.

This information seems to support Gardner’s theory that it’s the way the fruits are cultivated, rather than the fruits themselves, that render them toxic. Unfortunately, based on what Gardner uncovered during her investigation, we can’t assume organic raisins or grapes are safe, either, so my recommendation is to avoid feeding grapes, raisins, and related fruits to your pet.

6. Alcohol — Alcohol (ethanol) poisoning typically occurs when a dog samples an alcoholic beverage. Toxicity has also occurred in dogs who ate rotten apples, sloe (blackthorn) berries, and uncooked bread and pizza dough, all of which contain alcohol. Other potential sources of ethanol include paint and varnish, certain medications, perfume/cologne, mouthwash, and certain types of antifreeze.

Just as with humans, when a pet ingests alcohol, it is quickly absorbed from the gastrointestinal (GI) tract and reaches the brain. Symptoms develop within a short period of time, and include depression, loss of coordination, lethargy, sedation, increased body temperature, dangerously slow breathing, and coma.

7. Macadamia nuts — Macadamia nuts can cause serious problems for dogs, even in very small amounts. Symptoms of poisoning occur with 12 hours of ingestion and can include hind-limb weakness, vomiting, stiffness and loss of coordination, trembling, fever, abdominal pain, and pale mucous membranes.

8. Bread dough — Most bread dough contains yeast, and when exposed to a warm, anaerobic environment (like the oven or the inside of your dog), the enzymes in the yeast convert the sugar in the dough to ethanol (alcohol) and carbon dioxide. The carbon dioxide is what makes the dough rise, and the ethanol serves to flavor the bread as it evaporates during the process of baking.

There are two concerns for a dog that has eaten bread dough. One, there's a large mass of dough in the stomach that is continuing to rise, which can not only make your pet uncomfortable, but can also potentially rupture his stomach or bowel. Two, the warm environment of the stomach promotes ongoing fermentation of the alcohol in the dough, which can result in ethanol toxicosis.

9. Cooked bones — Cooked bones are dangerous to dogs because they tend to splinter. Most veterinarians have performed surgery to remove shards, splinters and blockages from dogs who were given or scavenged cooked bones. Tragically, some cases prove fatal.

With that said, it’s important to note that your dog’s ancestors and counterparts in the wild have been eating bones forever. Canines in their natural habitat eat prey, including the meat, bones and intestinal contents. In fact, your pet has a biological requirement for the nutrients found in bone marrow and the bones themselves.

Dogs also love to chew raw bones for the yummy taste, the mental stimulation, and also because all that gnawing is great exercise for the muscles of the jaw. So play it safe, and offer your dog only raw bones — either edible bones and/or recreational bones.

10. Sugary, salty, fatty, and processed people foods — Table scraps from holiday meals aren’t necessarily bad for your dog, depending on what the meal consists of and what ingredients are used. For example, cooked turkey meat is fine for dogs. A few fresh cooked veggies such as plain (no flavorings or additives of any kind) green beans or yams are also fine.

Examples of people food you'll want to avoid giving your pet include dressing (stuffing); processed or sugary foods; bread, rolls, and all desserts. Also, it’s best to blend a small portion of safe people food in with your dog's regular food and offer it at her usual mealtime. It's not a good idea to offer treats from your plate at the table, or in the kitchen during meal preparation or cleanup.

If You Think Your Dog Has Been Poisoned

If you suspect your dog or cat has ingested a poison and you have questions or need guidance, you can call the ASPCA’s Poison Control Center hotline at 1-888-426-4435, or the Pet Poison Helpline at 1-855-764-7661. Both hotlines can be reached 24 hours a day, 7 days a week, 365 days a year.

If you’re sure your pet has been exposed to a toxin, get her to your veterinarian or an animal emergency hospital immediately. If you know or suspect the substance your animal got into, bring it along.