Which foods are toxic to dogs?

Which Foods Are Toxic to Dogs?

You're enjoying a meal, and your dog looks up at you with those irresistible eyes. Sharing a small bite feels like a harmless act of affection—but some everyday foods can pose a serious risk to your dog's health.

Chocolate, grapes, onions, avocado and raw potatoes are among the foods that should never be fed to dogs. Their digestive system is very different from ours, and ingredients that are perfectly safe for people can be harmful—or even life-threatening—for our four-legged friends.

Here's a guide to the foods every dog owner should know to avoid.

1. Chocolate

Chocolate is one of the most dangerous foods for dogs.

It contains theobromine, a naturally occurring compound that dogs metabolise very slowly. As it builds up in the body, it can affect both the nervous system and the heart.

The darker the chocolate, the higher its theobromine content.

Possible symptoms include:

• Vomiting
• Diarrhoea
• Restlessness
• Tremors
• Increased heart rate
• Seizures in severe cases

If your dog eats chocolate, contact your veterinarian immediately.

2. Onions, Garlic and Other Alliums

Onions, garlic, shallots and leeks contain sulphur compounds that can damage a dog's red blood cells.

These ingredients are harmful whether they are raw, cooked, dried or powdered.

Over time they can cause haemolytic anaemia. Symptoms may not appear immediately but can include:

• Lethargy
• Pale gums
• Weakness
• Reduced appetite

If you suspect your dog has eaten these foods, seek veterinary advice.

3. Grapes and Raisins

Both fresh grapes and raisins can cause acute kidney failure in dogs.

Although researchers have not yet identified exactly why, the risk is well documented.

Signs may include:

• Vomiting
• Lethargy
• Loss of appetite
• Reduced or painful urination

Any ingestion should be treated as an emergency.

4. Avocado

Avocados contain persin, a natural compound that many animals—including dogs—do not tolerate well.

In dogs, it most commonly causes digestive upset such as vomiting and diarrhoea.

The flesh, skin and pit should all be avoided. The pit also presents a serious choking hazard and may cause intestinal blockage if swallowed.

5. Cooked Bones

Cooked bones are not chemically toxic, but they can be extremely dangerous.

Cooking makes bones brittle, causing them to splinter into sharp fragments that may:

• Injure the mouth
• Damage the stomach or intestines
• Cause intestinal obstruction

If you choose to feed bones, they should always be raw, appropriately sized and offered under supervision.

Related articles:

• How to Prepare a Balanced BARF Meal for Your Dog
• What Is the Best Meat for Your Dog?

6. Alcohol and Coffee

Dogs should never consume alcohol or caffeinated drinks.

Both can affect the nervous system and may lead to serious neurological or respiratory problems.

Fresh, clean water is always the best drink for dogs.

Milk, sugary drinks and fruit juices offer no nutritional benefit and may upset digestion.

7. Xylitol

Xylitol is an artificial sweetener found in many sugar-free products, including chewing gum, sweets and some baked goods.

Even small amounts can trigger a rapid release of insulin in dogs, leading to:

• Severe hypoglycaemia (low blood sugar)
• Liver damage
• Neurological symptoms

Xylitol poisoning requires immediate veterinary attention.

8. Raw Potatoes

Raw potatoes contain solanine, a naturally occurring compound that can irritate the digestive system and affect the nervous system.

Symptoms may include:

• Vomiting
• Diarrhoea
• Weakness
• Neurological signs

Cooking destroys most of the solanine, making cooked potatoes a safe and useful carbohydrate source when included in a balanced homemade diet.

9. Walnuts

Walnuts are not recommended for dogs.

Their high fat content may cause digestive upset and, in susceptible dogs, pancreatitis.

In addition, mouldy walnuts may contain mycotoxins capable of causing tremors and other neurological symptoms.

10. Macadamia Nuts

Macadamia nuts are highly toxic to dogs.

Signs of poisoning may include:

• Muscle weakness
• Difficulty walking
• Tremors
• Fever
• Lethargy

Although most dogs recover with prompt veterinary treatment, ingestion should always be treated seriously.

Frequently Asked Questions

Can I Share Table Scraps with My Dog?

Some plain foods can be shared occasionally, but many everyday ingredients should be avoided.

Never offer foods containing onions, garlic, chocolate, grapes, avocado or nuts.

It's also best to avoid highly processed foods that are rich in salt, sugar or fat, such as cured meats, sweets, ready meals or heavily seasoned pasta dishes.

Is a Small Amount of Chocolate Dangerous?

It depends on both your dog's size and the type of chocolate.

Dark chocolate and baking chocolate contain much higher levels of theobromine than milk chocolate.

Whenever chocolate has been eaten, contact your veterinarian without delay.

Do All Dogs React the Same Way?

No.

The severity of poisoning depends on several factors, including your dog's size, age, overall health and the quantity consumed.

Some dogs develop symptoms after only a very small amount, while others may appear well for several hours before becoming ill.

Whenever you're unsure whether a food is safe, it's always best to consult your veterinarian before offering it to your dog.