What foods are toxic and poisonous to dogs?

The risks and dangers of human foods to dogs

Not everything we eat is safe for our dogs to eat. Many foods are, in fact, toxic for dogs. 

Interestingly, 28% of dog owners believe their pets fell ill after consuming something toxic. Vets estimate that nearly 120,000 dogs were treated for food poisoning in 2021. 

There are other risks to feeding your dog human food, including:

• Dogs have a different digestive system than us: Your dog has a different digestive system than you, and human food can be too fatty for them to digest properly. Meaning it sits in their stomach, which can lead to an upset stomach, vomiting, diarrhoea, and more serious issues like pancreatitis.
• Foods may trigger an allergic reaction or sensitivity: Like us, dogs can be allergic, intolerant, or sensitive to just about anything. By feeding your dog human food with lots of different ingredients, you may inadvertently give them something that’s bad for them.
• Can endorse negative behaviour : You’ll probably do anything to make your dog happy. But giving the scraps of food to stop them whining, begging, or jumping up, can lead to a cycle of bad behaviour that can be hard to break.
• Contributes to weight gain: When you subscribe to Bella & Duke, we calculate the amount of food per day your dog needs to meet its nutritional needs. Feeding food that may be high in fat (which human food can be) may lead to weight gain.

A report for the PDSA found that 1 in 3 dogs in the UK is obese or overweight. You don’t want this for your dog. So avoid giving them scraps of food. 

The ultimate list of toxic foods and drinks for dogs

Alcohol

All alcoholic drinks, such as beer, wine, cocktails, spirits, and foods containing alcohol are toxic to dogs. Even a small amount can cause alcohol poisoning, particularly in small dog breeds. 

Symptoms of alcohol poisoning include: 

• Legarthy
• Lack of coordination
• Drooling
• Vomiting
• Weakness
• Decreased breathing 
• Weakness
• Low blood sugar
• Low blood pressure
• Low body temperature 

Avocado skin and stone

The skin and stone of the avocado contains a fungicidal toxin called persin. 

Symptoms of persin poisoning include: 

• Diarrhoea
• Vomiting
• Pancreatitis
• Heart issues 

The flesh of an avocado only contains tiny amounts of persin, so it is safe to feed to your dog in small amounts and in moderation. In fact, avocado provides many benefits to dogs, such as supporting a healthy immune system and joint health. 

Blue cheese

Blue cheese can produce a toxin called roquefortine C and this is toxic for dogs. Mould can also be present on the rind of blue cheese, which can contaminate the cheese.  

If your dog eats blue cheese, they may develop: 

• Seizures
• Vomiting
• Diarrhoea 
• High temperatures 

Black walnuts

Black walnuts and the black walnut tree contain a toxin called juglone that can develop on the fruit and bark of the tree. 

Symptoms of black walnut poisoning include: 

• Stomach problems
• Vomiting
• Diarrhoea 

Bread dough

If ingested, bread dough poses a number of risks to dogs: 

1. The stomach acts like an incubator for dough, making it expand and pressing on the gastric wall. Eventually, it can cause respiratory problems 
2. When yeast ferments, it produces ethanol (also found in alcohol), which is absorbed into the bloodstream, causing lethargy, vomiting, and diarrhoea

Brie

The rind of Brie cheese can contain a toxin called aflatoxin. When aflatoxin levels build up, it can cause: 

• Loss of appetite
• Sluggishness
• Yellowing of the skin, eyes, and gums
• Diarrhoea
• Unusual bleeding 

The cheese may also contain a bacteria called listeria, which can cause diarrhoea and vomiting, fever, and muscle pains.

Caffeine

Dogs are more sensitive to caffeine than humans, so for small dog breeds a tiny amount could affect them. 

Caffeine is found in coffee, tea, chocolate, sports drinks, and even soft drinks. 

Symptoms of caffeine poisoning include: 

• Hyperactivity
• Vomiting
• Elevated heart rate
• High blood pressure
• Abnormal heart rate 
• Seizures
• High body temperature

Cherries

While the flesh of a cherry is safe for dogs to eat, the pits, stones, stems, and leaves contain cyanide, which is toxic to dogs.

Symptoms of cyanide poisoning include: 

• Salivation 
• Difficulty breathing
• Convulsions
• Paralysis 

The number of cherries a dog needs to ingest before it becomes toxic depends on the size of the dog. 1 or 2 cherry pits may be enough to bring on symptoms for small dogs. 

Cheese spread

You should avoid feeding dogs cheese spread because it is typically highly processed, high in sodium, hydrogenated fats, and lactose. Many cheese spreads also include additional ingredients, such as onions and chives, which can be highly toxic to dogs in certain quantities.

How much a dog needs to ingest before cheese spread becomes toxic depends on the ingredients in the spread and the size of the dog. 

Chocolate

Chocolate is toxic to dogs due to the presence of theobromine, a chemical linked to tremors, agitations, heart problems, and kidney failure.

The levels of theobromine are higher in darker chocolate. However, no chocolate is suitable for dogs. While white chocolate may have lower levels of theobromine, it is still likely to cause an upset stomach in dogs.

Depending on the amount and type of chocolate your dog has eaten, they may need to be taken to the vet as quickly as possible. This handy calculator will help you to work out if your dog has eaten a dangerous amount.

Cooked bones

While not toxic, cooked bones should never be given to dogs. Cooking changes the structure of the bone, making it brittle, which can easily shatter when a dog bites on it. Shattered pieces of bone pose a choking risk, and if swallowed, can damage the digestive tract. 

Elderberries

Ripe elderberries, when eaten in small quantities, are safe for dogs, the leaves, stem, roots, and unripe fruits aren’t as they contain cyanide. 

While it’s unlikely your dog will ingest these, if they do, they may experience: 

• Vomiting
• Diarrhoea
• Dizziness
• Legarthy 

Grapes, raisins, currants, and sultanas

It’s known that grapes, currants, raisins, and sultanas are extremely toxic to dogs, but the reason why isn’t known.  

Consuming just one raisin or grape can be fatal for dogs, as it can lead to acute kidney failure.

Other symptoms of grape (and related foods) poisoning include: 

• Abdominal pain
• Lethargy
• Weakness
• Dehydration
• Tremours 

It’s important not to feed your dog foods containing grapes, raisins, etc., such as mince pies, cakes, or puddings, as these will also be toxic for them. 

Grapefruit

While the flesh of a grapefruit is not toxic for dogs, the skin or peel is because of psoralens and the natural oils in the skin. It’s also quite tough to digest, so could pose a potential choking or blockage risk.  Meaning dogs must not be fed grapefruit skin/peel.

Symptoms of grapefruit poisoning include: 

• Vomiting
• Diarrhoea
• Depression
• Skin irritation 

Gravy

You may think gravy will make a tasty topper for the pet’s dinner, it can often contain a lot of salt and sometimes onions! This can lead to salt toxicity and dehydration in your furry friend. 

Instead of gravy, try some delicious bone broth which will give your dog all the flavour, with none of the risk. 

Macadamia nuts

This is frequently listed as one of the most toxic human foods for dogs. Surprisingly, it’s not known why macadamia nuts are toxic. 

Extra caution has to be taken with this nut as little as 1/10 of an ounce can be dangerous. 

Symptoms of macadamia nut poisoning include: 

• Weakness
• Depression
• Vomiting
• Lack of muscle control
• Difficulty walking
• Tremours
• Raised temperature

Mouldy foods

Mycotoxins form when food like bread, pasta, cheese, nuts, fruits, and other food matter starts to grow mould. Mycotoxins are toxic to dogs, and if ingested can make your dog have: 

• Seizures
• Diarrhoea
• Vomiting
• Drooling
• Lack of coordination
• Appetite loss
• Stomach pains
• Dehydration

In severe cases, eating mouldy food may be deadly. 

If you compost your food waste, ensure that the food bin/container is securely fastened or place it somewhere your dog can’t access. 

Onions, chives, shallots, and leeks

These vegetables are part of the Allium family of plants and are considered toxic to dogs. Raw or cooked, they shouldn’t be given to dogs. 

If your dog does ingest them, they may experience: 

• Upset stomach
• Vomiting
• Diarrhoea
• Reduced appetite
• Dehydration 

Peanuts and peanut butter

Aflatoxins are toxins found in certain crops including peanuts and tree nuts (to note, peanuts are not nuts but legumes). 

Ingesting aflatoxins is a common reason for poisoning in dogs, and exposure has been linked to increased risks of liver cancer. So, it’s best not to feed your dog peanuts, peanut butter, or foods containing both.

This is not all though. There are 5 key reasons dogs shouldn’t eat peanuts or peanut butter.

Salt

While salt is an essential part of the diet, too much salt, table salt in particular, puts strain on your dog’s kidneys, meaning salted foods have the potential to be ‘toxic’, regardless of other ingredients.

Symptoms of salt poisoning in dogs include: 

• Vomiting
• Diarrhoea
• Seizures

To prevent this, make sure any foods that dogs consume are not loaded with salt.

Sugar (sweets and sugary drinks)

While natural sugars in small amounts aren’t dangerous for dogs. If consumed in large quantities, it can lead to numerous health problems like an upset stomach, obesity, diabetes, and pancreatitis. Refined sugar and products containing it should be avoided. 

Foods and drinks that contain sugar and artificial sugars (xylitol), are toxic to dogs. These include things like chocolate, sweets, sports drinks, and soft drinks.

Xylitol

Xylitol is a commonly found sweetener added to foods for human consumption. This is incredibly toxic to dogs, with even the smallest quantities causing a sudden release of insulin, which lowers blood sugar. Often, the liver is severely damaged by xylitol, which can cause liver failure. 

Xylitol may also be listed on the ingredients list as ‘Birch Sugar’.

Foods to avoid feeding to your dog

If your dog accidentally ingests a small amount of these foods, it may cause an upset stomach, but it won’t require a visit to the vet. Avoid giving the following foods to your dog.

Citrus fruits

Lemon and limes are particularly problematic for dogs because of the citric acid that is found in the flesh. Psoralen, which is a phototoxic, is found in the rind and skin of lemons and limes, and this can trigger an allergic reaction. 

If large enough quantities of lemons and limes are ingested, your dog may experience: 

• Vomiting
• Diarrhoea
• Legarthy 

Gooseberries

Both the gooseberry plant and unripe berries shouldn’t be fed to dogs because they contain glyoxylic acid, which if eaten in large quantities can lead to kidney stones. 

King mackerel

Mercury enters rivers and oceans through industrial processes, and this builds up in fish. King mackerel are a large, long-living fish which means that mercury levels are high. 

Symptoms of mercury poisoning include: 

• Hair loss
• Anxiety or nervousness
• Blindness
• Kidney damage
• Loss of coordination
• Tremours
• Vomiting blood
• Bloody diarrhoea 

Additionally, king mackerel may have parasites living in their skin, muscles, and internal organs. 

The quantity of king mackerel a dog needs to ingest before it becomes toxic depends on the dog’s size.

Shark

Sharks are long-living and large fish, meaning their mercury levels are high, which is toxic to dogs. 

Swordfish

Swordfish is another long-living and large fish. Mercury levels in swordfish can be high, so avoid feeding it to your dog. 

Tilefish

Tilefish can be toxic to dogs if eaten in large quantities, due to its high mercury levels. Bacteria and parasites may also be found on its skin and muscles, which can be harmful to dogs. 

Tuna

A small amount of tuna is not going to harm your dog, but consuming a large amount may lead to mercury poisoning. 

Signs of poisoning and what to do 

The smaller the dog’s size, the quicker the symptoms of poisoning develop. Here are the signs to look out for:

• Diarrhoea
• Blood present in their poo
• Seizures or tremors 
• Becoming hyperactive
• Feeling lethargic or unsteady on their feet
• Bleeding around the gums, nose, ear flaps, or groin 
• Discoloured poo 

Contact your vet immediately if you suspect your dog has eaten something toxic or is exhibiting symptoms such as an elevated heart rate, tremors, or seizures.

It will help if you have the following information to hand:

1. How much your dog weighs
2. How much of the item your dog has eaten
3. What type of food they have eaten 

Your vet may ask you to bring a sample of what you think your dog has swallowed. 

Vetts.app 24/7 for Bella+Duke customers

While you try your hardest to keep your dog happy and healthy, there will be times when they’re not 100%. It’s tough for you to see them suffering. For Bella+Duke customers, free vet help is on hand. 

We’ve partnered with Vetts.app to provide free 24-hour access to a vet helpline. Immediate access to vet help is imperative if you think your dog has eaten something toxic. The quicker you act, the better the outlook is for your dog.

Additionally, if you suspect your dog has swallowed something toxic, you will need to tell the vet or nurse: 

• What it is 
• How much they have swallowed
• When it happened
• If they are displaying any symptoms

Tips for a poison-proof home

No matter how careful you are, a curious dog may be able to get its paws onto something harmful. To create a poison-proof home, consider: 

• Sweeping during and after food prep
• Clearing the dinner table immediately once everyone has finished eating
• Reminding guests not to feed your dog food off their plate
• Reminding children not to leave snacks lying around
• Making sure all cupboard doors shut properly 
• Thinking about fitting locks to cupboards or the pantry if your dog is clever and has figured out how to open them
• Investing in a dog-proof bin or putting your bin in a cupboard to prevent your dog from eating mouldy food 
• Clearing out children’s lunch bags once they are home
• Not leaving half-drunken cups of tea and coffee lying around
• Putting up a sign to remind people to put the toilet seat down so your dog doesn’t take a sip out of it  

Additional tips: 

• Keep household cleaners in a locked cupboard
• Store medication in a cupboard placed high up
• Keep house plants out of reach