Human Food That is Poisonous to Dogs and What You Need to Know

Sharing food with your dog might feel like a natural thing to do. It often starts with a bite of toast, a corner of cheese or a leftover scrap from dinner. For many owners, it feels like a way of showing love. But not everything we eat is safe for dogs. In fact, some foods that are completely fine for us can be highly poisonous to them.

This post is part of The Dog Dish Series at Paws Academy, where we break down everyday risks that every dog owner should understand. No drama. Just calm, useful advice you can actually apply.

Dogs have different digestive systems to humans. What we break down easily can overwhelm their organs or upset their entire system. And because dogs come in all sizes and have different tolerances, even small amounts of certain foods can lead to serious problems.

Why Dogs Cannot Eat What We Eat

A dog’s body works differently to ours. Some of the ingredients we use every day are toxic to dogs because their liver processes chemicals in a different way. Foods that seem harmless, like grapes, onions or even sugar-free chewing gum, can cause severe reactions in dogs, from vomiting and diarrhoea to seizures or sudden collapse.

It is not just about large quantities either. In many cases, even a single bite can be dangerous. The smaller the dog, the higher the risk. But even large dogs are not immune. The effects may just take longer to show or build up quietly over time.

Common Foods That Are Poisonous to Dogs

Chocolate

Chocolate contains a chemical called theobromine, which dogs cannot process. Dark chocolate is the most dangerous, but even milk chocolate can be toxic in the right quantity. Symptoms include vomiting, restlessness, tremors and, in severe cases, seizures or heart failure.

Grapes and Raisins

Grapes, sultanas, raisins and currants can all cause kidney failure in dogs. The reaction is unpredictable. Some dogs show signs after just one or two. Others may eat more without immediate symptoms but still suffer long-term damage.

Onions and Garlic

These common ingredients, whether raw, cooked, powdered or dried, can damage red blood cells and lead to anaemia. They are often hidden in soups, gravies, sauces and leftovers. Dogs affected may become weak, lethargic or show signs of pale gums.

Xylitol

Xylitol is a sugar substitute often found in chewing gum, sugar-free sweets, peanut butter and even some baked goods. It can cause a rapid drop in blood sugar and, in some cases, liver failure. Early signs include vomiting, loss of coordination and collapse.

Alcohol

Even small amounts of alcohol can be dangerous to dogs. It depresses the nervous system and can lead to vomiting, difficulty breathing, coma or death. It is not just drinks either. Alcohol can also be found in desserts, sauces or raw bread dough.

Avocado

Avocado contains a toxin called persin which can cause vomiting and diarrhoea. While some dogs tolerate small amounts, the risk increases depending on the variety and the part of the plant consumed. The stone is also a choking and blockage hazard.

Macadamia Nuts

These nuts can cause weakness, vomiting, tremors and an increase in body temperature. Reactions can happen within hours and are often severe, even if the amount eaten was small.

Caffeine

Caffeine is found in coffee, tea, energy drinks and even some painkillers. It affects the heart and nervous system, leading to restlessness, elevated heart rate, tremors or seizures.

Understanding Toxicity Levels

Some foods are dangerous because of a specific compound or chemical, while others become harmful based on quantity or frequency. Chocolate, for example, is more toxic the darker it is. Grapes and raisins are dangerous regardless of the quantity, while too much fat from leftovers may cause issues only if given repeatedly.

The severity of the reaction also depends on the size, age and health of your dog. A large, healthy adult dog may tolerate more than a small puppy or a senior dog with existing health concerns. But it is always better to play it safe. No food is worth the risk.

Less Obvious Risks to Watch For

Not every danger comes from a food that is obviously toxic. Some risks come from how food is prepared, stored or flavoured.

Cooked Bones

Cooked bones, especially from poultry, can splinter and cause choking or serious injury to your dog’s digestive tract.

Fatty Foods

Greasy leftovers, skin from roasted meat or large amounts of cheese can cause pancreatitis, a painful condition that affects digestion and often requires emergency care.

Mouldy Food or Rubbish

Dogs that get into the bin may eat mouldy or spoiled food which can contain dangerous toxins. These toxins can lead to muscle tremors, vomiting and problems with coordination.

Salt and Seasonings

High levels of salt or spice can upset your dog’s stomach or lead to dehydration. Salt poisoning is rare but serious and can happen if a dog eats salted meat, crisps or savoury snacks.

What Makes Certain Foods Toxic to Dogs

Dogs lack the enzymes needed to process certain ingredients. In the case of chocolate and caffeine, the stimulant compounds build up in the system and put strain on the heart. Xylitol fools a dog’s pancreas into releasing insulin, which causes a dangerous drop in blood sugar. Grapes and raisins contain compounds that directly damage kidney tissue, even though the exact chemical has not been fully identified.

Just because a food is plant-based or natural does not mean it is safe. Many toxins found in fruit, nuts and herbs can have devastating effects on dogs, even if they are considered healthy for humans.

Real-life Scenarios and Common Mistakes

Most poisonings happen by accident. A dog might get into a shopping bag, steal something from a table, or be fed a small treat by a well-meaning friend. Children may offer sweets without knowing the risk. Some owners are unaware that something like peanut butter could contain xylitol, or that their dog has pulled a chocolate wrapper from a handbag.

It only takes a moment of distraction. That is why awareness is just as important as prevention.

Creating a Dog-safe Kitchen and Home

Start by storing all food out of reach. Keep worktops clear and bins secured. Label food items clearly, especially those that contain xylitol or caffeine. Teach children never to feed the dog from their plate or snacks. If visitors come over, let them know not to give any food without checking with you first.

If your dog is a known scavenger, consider using baby gates to keep them out of the kitchen during cooking or mealtimes. Routine is powerful. The more consistent your dog’s boundaries are around food, the safer they will be in the long run.

When Symptoms Are Delayed

Some toxic reactions happen quickly. Others do not show for hours or even days. A dog who eats raisins may seem fine for a while, only to collapse from kidney failure later that night. Dogs who ingest alcohol might appear drowsy, then suddenly stop breathing. Xylitol can trigger seizures within an hour but cause liver failure a day later.

Do not wait for symptoms. If you suspect your dog has eaten something harmful, act straight away.

Educating Children and Visitors

Dogs are part of the family, but they rely on humans to keep them safe. Children love to share, especially with pets they adore. But without education, they may unknowingly put your dog in danger. The same goes for visiting friends or relatives.

Have clear rules in place. Keep safe treats available that children can offer under supervision. Let guests know that some foods in your home are off-limits for your dog. Most people are happy to help once they understand the risks.

What to Do If Your Dog Eats Something Toxic

If you suspect your dog has eaten something poisonous, call your vet immediately. If it is outside of normal hours, contact the nearest emergency veterinary service.

Provide as much detail as possible. What was eaten, how much, how long ago and whether the packaging is available. This information can make a critical difference in treatment.

Do not wait for symptoms and do not try to treat it yourself. Some poisons are made worse by vomiting, while others require very specific treatment.

Safe Treats You Can Offer Instead

There are plenty of healthy, dog-friendly options if you want to share a little something with your pet. Try carrot sticks, cucumber, plain boiled chicken, green beans, a few blueberries or a slice of apple with the core and seeds removed.

These foods are simple, safe and often enjoyed just as much as human food. What matters most is how the treat is given. Your presence and attention mean far more to your dog than what is in the food itself.

Prevention is Always Better Than Cure

No one means to harm their dog. Most poisoning cases are simply the result of not knowing. That is why education is so important. Once you understand the risks, you can adjust your habits and home environment without making life difficult or restrictive.

Dogs do not know what is dangerous. It is up to us to protect them from everyday risks that are easy to avoid once we know they exist. Keep your vet’s number handy. Know what foods to avoid. Stay curious and cautious.

This post is part of The Dog Dish Series by Paws Academy, where we look at the real-life details that help keep dogs safe, well and thriving. Whether it is food, first aid or daily routine, the small decisions you make today can shape a longer, healthier life for your dog.