What foods are poisonous to dogs?

Many foods that are perfectly safe for us can be extremely dangerous for dogs. Research suggests that dogs account for 70–80% of all animal poisoning cases, and over 90% of exposures happen accidentally in the home. 

Their natural curiosity and tendency to investigate anything that looks or smells interesting means that they can easily eat something they shouldn’t. Learning which foods are poisonous to dogs is one of the best ways to keep them safe, prevent serious illness and avoid emergency trips to the vet.

In this article:

• Understanding why certain foods are toxic to dogs
• What are the top 10 most toxic foods for dogs?
• Other foods that are dangerous to dogs
• What to do if your dog eats something toxic
• Protect your pooch from everyday hazards

Understanding why certain foods are toxic to dogs

Dogs digest and process certain chemicals very differently from humans, which means some everyday foods can quickly become dangerous for them. 

Common foods like chocolate, onions and xylitol (a sweetener found in many products) contain compounds that dogs can’t break down safely. Other foods - such as grapes and raisins - can trigger reactions even in small amounts. Knowing how these reactions happen can help you spot problems early and keep your dog safe.

What are the top 10 most toxic foods for dogs?

Some foods pose a much higher risk to dogs than others, either because they contain potent toxins or can cause serious illness even in small quantities. Here’s our list of the 10 foods most poisonous to dogs.

1. Chocolate and caffeine

Chocolate is one of the most toxic foods for dogs, mainly because it contains two stimulants - theobromine and caffeine - that dogs process far more slowly than we do. This means the effects build up quickly, even from small amounts. Dark chocolate and cocoa powder contain a higher concentration of these chemicals, making them more harmful to your pooch.

Research shows that dogs may start to show signs of chocolate poisoning - including vomiting and diarrhoea - after eating as little as 20 mg per kg of these compounds. This is roughly the amount found in a small piece of dark chocolate for a medium-sized dog. 

Larger amounts can cause even more serious issues, leading to heart problems or even seizures.

2. Grapes, raisins and sultanas

Grapes and their dried varieties (raisins, currants and sultanas) are among the foods poisonous for dogs, and worryingly, even small quantities can be dangerous. 

Studies have shown huge variation in how dogs react to ingesting grapes - with some becoming seriously ill after eating a handful, while others can eat larger amounts and may not show any symptoms at all. Because the toxic dose is unpredictable, any ingestion should be treated with caution.

3. Onions, garlic and other alliums

Onions, garlic, leeks and chives all belong to the allium family. They contain natural sulphur-based compounds that can damage your dog’s red blood cells, leading to a type of anaemia that causes weakness and can make your dog seriously ill. 

These ingredients appear in many home-cooked dishes, so even leftovers can be a problem. Signs to look out for include vomiting, diarrhoea, pale gums, tiredness and dark-coloured urine.

4. Xylitol (sugar-free sweetener)

Xylitol is a sugar substitute found in products like gum, sweets, peanut butter and even toothpaste. In dogs, it can cause a sudden and life-threatening drop in blood sugar.

Even very small amounts (as little as 0.03 g per kg) can cause hypoglycaemia, while ingesting larger quantities has been linked to liver failure. Symptoms can develop quickly, often within 30–60 minutes, and may include vomiting, collapse, tremors or seizures.

5. Alcohol

Although it’s not a food, it’s important to be aware of the risks. Alcohol affects dogs much more quickly and severely than it does humans, and even small amounts can lead to vomiting, drowsiness, breathing difficulties and a dangerous drop in body temperature. In more serious cases, dogs may experience tremors, seizures or even slip into a coma.

Scientific reviews report cases of dogs becoming intoxicated after drinking alcoholic beverages or eating fermented fruits, highlighting just how easily accidental exposure can happen.

6. Raw bread dough

Raw bread dough poses a double threat to dogs. As the yeast ferments in the warm, moist environment of the stomach, it releases alcohol (ethanol) and expands, which can cause painful bloating alongside signs of intoxication. 

Even though alcohol in bread dough is probably the furthest thing from our minds, knowing about the dangers is essential for keeping it out of reach in future. 

7. Macadamia nuts and other nuts

Macadamia nuts are well known for being poisonous for dogs, often causing neurological symptoms within 12 hours of ingestion. Studies have reported symptoms from doses as low as 0.7 g per kg, including wobbliness, trembling, vomiting, stiffness and fever.

Other nuts, including walnuts, aren’t technically toxic but can upset your dog’s stomach. Some can also be high in fat, which increases the risk of pancreatitis.

Plain, unsalted peanuts are safe in small amounts, but peanut butter must be checked carefully for xylitol.

8. Avocado

Avocado contains a natural substance called persin, which can irritate your dog’s stomach and cause sickness. While dogs aren’t as sensitive to persin as some species, avocado flesh is also high in fat, which may trigger vomiting, diarrhoea or pancreatitis.

The stone is a choking and blockage risk too, so it’s best to keep avocados well out of reach.

9. Fruit stones, seeds and pips

Many fruits are safe for dogs - including watermelon, bananas, blueberries, apples and strawberries. However, you should be mindful of certain seeds, stones, and cores. 

Apple seeds contain naturally occurring chemicals (cyanogenic compounds) that can be harmful in large amounts, while stones from cherries, peaches and plums pose a choking risk or could block your dog’s intestines.

Remember: Always remove any pips or stones before sharing fruit with your dog.

10. Wild mushrooms

Wild mushrooms can be one of the top 10 toxic foods for dogs, as certain species contain potent toxins that can make dogs seriously unwell. While many mushrooms are harmless, it’s extremely difficult to tell the safe varieties from the dangerous ones.

Some toxins irritate the stomach, causing vomiting and diarrhoea within a few hours, while others affect the nervous system and may lead to drooling, trembling, disorientation or seizures. More serious types can damage the liver or kidneys, with signs such as jaundice, increased thirst or extreme tiredness.

Other foods that are dangerous to dogs

As well as those featured in list above, there are a few other foods that probably aren’t eaten as often but can still be harmful to your pooch: 

• Raw or green tomatoes and potatoes: These contain solanine, which can cause tummy upsets and, in larger amounts, may lead to weakness or disorientation.
• Corn on the cob: Plain corn is safe in moderation, but the cob itself can easily become lodged in your dog’s intestines, making it a serious choking and blockage hazard.
• Hops (used in brewing): Hops have been linked to a dangerous rise in body temperature in dogs (malignant hyperthermia), so keep home-brewing supplies well out of reach.
• Mouldy foods: Mouldy bread, nuts or cheeses can contain toxins that affect the nervous system, sometimes leading to tremors or seizures.

What to do if your dog eats something toxic

If your dog manages to eat something potentially harmful, try not to panic. However, you should still act as quickly as you can. Some toxins can take effect within minutes, while others develop over several hours. Veterinary studies show that fast treatment gives dogs the very best chance of recovery, especially in cases involving chocolate, xylitol or grapes.

Small dogs can be affected more severely because it takes much less of a toxic food to make them unwell, but any dog, regardless of size, can become poorly if the quantity is high enough.

Symptoms to look out for

Get in touch with your vet straight away if you notice any of the following:

• Vomiting or diarrhoea
• Excessive drooling
• Lethargy, weakness or collapse
• Tremors, twitching or seizures
• Restlessness, pacing or hyperactivity
• Pale gums or dark “tea-coloured” urine
• Rapid breathing or changes in heart rate
• Increased thirst or reduced urination
• Signs of abdominal pain

Animal Friends customers can access free 24/7 video vet advice through Joii Pet Care, meaning you can speak to an expert immediately if you’re worried.

Important: If your dog shows severe symptoms including seizures, collapse, difficulty breathing, uncontrollable vomiting or vomiting blood - this is considered an emergency and you’ll need to get your dog to a vet clinic right away. 

Protect your pooch from everyday hazards

Dogs are naturally curious, and accidents can happen even in the most careful homes. By staying aware of the foods poisonous and harmful to dogs, you can help keep your best friend safe.

Pet insurance can help cover the cost of unexpected veterinary treatment if they become unwell, offering peace of mind when you need it most. If you’re interested in exploring our coverage options, view our Dog Insurance page for more details. 

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