Foods Toxic to Dogs: What Owners Need to Avoid

Updated September 2026

Most dogs are very interested in what we eat.

Unfortunately, some perfectly ordinary human foods can be dangerous to them.

Chocolate, grapes, raisins, onions, garlic and products containing xylitol are among the foods that can cause genuine poisoning in dogs. Other foods, such as cooked bones and corn cobs, are not technically poisons but can still cause serious injuries or intestinal blockages.

That distinction matters.

This guide focuses on foods that can be toxic to dogs, explains some of the other common food hazards worth knowing about, and tells you what to do if your dog eats something they should not.

For everyday feeding advice, start with my Dog Food & Nutrition Guide.

If your dog has already eaten something potentially poisonous, go to Dog Poisoning: What to Do If Your Dog Eats Something Toxic.

Important: If you think your dog has eaten something toxic, contact your veterinary practice promptly. Do not wait for symptoms to develop and do not try to make your dog vomit unless a veterinary professional specifically tells you to do so.

The foods I would keep away from dogs

The main food hazards I think every owner should recognise are:

• chocolate and cocoa
• grapes
• raisins
• sultanas
• currants
• onions
• garlic
• leeks
• shallots
• chives
• xylitol or birch sugar
• alcohol
• caffeine
• macadamia nuts
• mouldy food
• uncooked bread dough
• excessive amounts of salt

This is not an exhaustive list.

If your dog eats something and you are unsure whether it is safe, contact your vet or an appropriate animal poison service rather than relying on a social-media post or trying to calculate the risk yourself.

The PDSA guide to poisons and hazards and Animal PoisonLine’s harmful-food guidance are useful UK sources.

Chocolate

Chocolate is one of the best-known food hazards for dogs.

It contains theobromine, a substance dogs process much more slowly than people do.

The risk depends on several things, including:

• the type of chocolate
• the cocoa content
• how much was eaten
• the dog’s weight

Dark chocolate and cocoa products are generally more dangerous than milk chocolate because they contain more theobromine.

Possible signs of chocolate poisoning include:

• vomiting
• diarrhoea
• restlessness
• agitation
• increased heart rate
• tremors
• seizures

Do not wait for these signs before contacting your vet.

If possible, keep the wrapper so you can tell the vet exactly what type of chocolate your dog ate and approximately how much.

Animal PoisonLine notes that even relatively small quantities of dark chocolate can cause significant problems.

Grapes, raisins, sultanas and currants

These deserve particular caution.

Grapes and their dried forms can cause serious kidney damage in dogs.

The difficulty is that owners have no reliable way to predict which dog will be affected or what amount will cause a problem.

That means I would not use a rule such as:

“My dog only ate one grape, so it should be fine.”

Contact your veterinary practice or Animal PoisonLine if your dog has eaten grapes, raisins, sultanas or currants, even if they currently appear well.

These fruits can also be hidden in:

• fruit cake
• Christmas cake
• Christmas pudding
• mince pies
• hot cross buns
• cereal
• trail mix
• some biscuits
• chocolate-covered raisins

Animal PoisonLine advises contacting them even when a pet has not yet developed symptoms because poisoning can occur after small quantities.

Onions, garlic, leeks, shallots and chives

These all belong to the allium family.

They can damage a dog’s red blood cells and cause anaemia.

They remain a potential problem whether they are:

• raw
• cooked
• dried
• powdered
• included in seasoning
• incorporated into another food

This is why onion or garlic powder in sauces, gravies and seasoning mixes can matter just as much as a visible piece of onion.

I would not deliberately give garlic to a dog for health benefits or flea prevention.

An older version of this article suggested that small quantities of garlic could be safe and referred to garlic supplements for fleas. I no longer recommend that advice.

Current veterinary poisoning guidance includes garlic alongside onions, leeks, shallots and chives as foods that can cause toxicity.

If your dog has eaten a significant or unknown quantity of one of these foods, contact your vet.

Xylitol or birch sugar

Xylitol is a sweetener that can be extremely dangerous to dogs.

It may also appear on a label as birch sugar.

It can cause a rapid release of insulin, leading to dangerously low blood sugar, and can also cause liver damage.

Products that may contain xylitol include some:

• sugar-free chewing gums
• sweets
• baked goods
• dental products
• supplements
• nut butters
• low-sugar products

The important word here is some.

Do not assume every peanut butter contains xylitol, but always check the ingredient list before offering a product to your dog.

If your dog eats something containing xylitol, contact your vet promptly.

Animal PoisonLine specifically identifies xylitol as a poisoning risk because of low blood sugar and possible liver damage.

Alcohol

Dogs should not be given alcohol.

That includes obvious drinks such as:

• beer
• wine
• spirits
• cocktails

It can also appear in:

• alcoholic desserts
• liqueur chocolates
• uncooked fermenting dough
• spilled drinks

Alcohol can affect the nervous system and cause wobbliness, drowsiness, low body temperature, low blood sugar and, in severe cases, coma.

Keep glasses and bottles somewhere your dog cannot investigate them.

This is especially relevant at parties, barbecues, and picnics, where drinks are often placed on the floor.

Caffeine

Dogs are more sensitive to caffeine than people.

Potential sources include:

• coffee
• coffee grounds
• tea
• tea bags
• energy drinks
• caffeine tablets
• some medications
• chocolate

A quick lick of the remains of a cup is very different from swallowing coffee grounds or caffeine tablets, so the actual product and quantity matter.

If your dog has swallowed a concentrated caffeine product, contact your vet.

Signs can include agitation, tremors, increased heart rate and seizures. (Animal PoisonLine)

Macadamia nuts

Macadamia nuts can poison dogs.

Signs may include:

• weakness
• lethargy
• stiffness
• tremors
• increased body temperature
• vomiting

Chocolate-coated macadamias create an additional chocolate risk.

Current Blue Cross and Animal PoisonLine guidance both identify macadamia nuts as toxic to dogs.

Contact your vet if your dog has eaten them.

Mouldy food

The kitchen bin and compost heap can be surprisingly dangerous.

Some moulds produce toxins that can cause neurological symptoms in dogs.

Signs can include:

• vomiting
• twitching
• tremors
• high body temperature
• seizures

Animal PoisonLine warns that mouldy food can cause rapid neurological signs and can be harmful even after relatively small amounts.

Secure bins and compost so your dog cannot help themselves.

This is particularly important for enthusiastic scavengers.

Raw bread dough

Uncooked yeast dough creates two problems.

First, it can keep expanding in the stomach.

Second, fermenting yeast can produce ethanol, creating a risk of alcohol poisoning.

Animal PoisonLine lists abdominal swelling, vomiting, possible obstruction and alcohol intoxication among the risks.

If your dog eats a quantity of raw bread dough, contact your vet.

Salt

Dogs need sodium as part of a balanced diet.

That does not mean eating a large quantity of salt is safe.

Significant ingestion of substances such as table salt, dishwasher salt or very salty products can cause poisoning.

Signs can include vomiting, increased thirst, lethargy and, in severe cases, neurological problems.

Do not use salt or salt water to try to make a dog vomit.

That old home remedy can itself cause serious poisoning.

What about avocado?

Avocado is a good example of why I do not like enormous online lists where every food is labelled “toxic”.

The situation is more nuanced.

PDSA notes that persin in avocado is highly toxic to some species but that small amounts of avocado flesh are generally much less concerning in dogs. The high fat content can still cause digestive problems, and the large stone presents a choking or intestinal-blockage risk.

For those reasons, I do not use avocado as a dog treat.

But I would not put a small piece of avocado flesh in the same risk category as grapes, xylitol or dark chocolate.

That distinction makes this guide more useful.

Dangerous foods without actually being poisonous

Some things regularly appear on “toxic food” lists, even though toxicity isn’t really the problem.

They can still be dangerous.

Cooked bones

Cooked bones can splinter, damage the mouth or digestive tract, get stuck, or cause an obstruction.

That is a physical injury risk rather than poisoning.

I would not feed cooked bones.

Corn cobs

Corn itself is not the main problem.

The cob is.

Dogs can swallow large pieces that may become lodged in the gastrointestinal tract and require emergency treatment.

Keep discarded corn cobs away from dogs, particularly around barbecues and picnics.

Fruit stones and pits

Peach, plum and similar fruit stones can present choking and obstruction risks.

The simplest approach is to remove stones before offering any suitable fruit.

My Safe Fruits for Dogs guide covers fruit preparation in more detail.

Wooden skewers and food packaging

These are not food toxins, but dogs often swallow them while trying to reach the food attached to them.

Skewers can cause serious internal injuries.

Foil, cling film, wrappers and other packaging can also cause gastrointestinal problems or blockages.

Very fatty food

Rich fatty foods are not necessarily poisons.

However, large amounts may cause digestive upset and can be particularly problematic for dogs prone to pancreatitis.

That is another reason to avoid them.

Not every human food is dangerous.

The fact that certain human foods are poisonous does not mean dogs must never eat anything from a human kitchen.

Many healthy dogs can have small amounts of suitable foods such as:

• plain cooked chicken
• plain turkey
• suitable vegetables
• blueberries
• strawberries
• small pieces of apple with the core and seeds removed

The important questions are whether the food is:

• safe for dogs
• prepared appropriately
• suitable for that particular dog
• offered in a sensible amount

For the broader feeding picture, see my Dog Food & Nutrition Guide.

My Safe Fruits for Dogs guide also separates genuinely unsafe fruits from those you can feed appropriately.

Human food should not replace a balanced dog diet.

I am also changing another piece of advice from the previous version of this page.

I no longer recommend casually creating a dog’s meals by combining assorted human foods simply because variety sounds healthier.

Nutrition is more complicated than that.

For most healthy dogs, a sensible starting point is a complete dog food appropriate for the dog’s life stage.

Human food and suitable treats can be occasional extras where appropriate.

Dogs with medical conditions, allergies, pancreatitis, diabetes, kidney disease or prescribed diets may need very different rules.

My Dog Food & Nutrition Guide explains this in much more detail.

What should I do if my dog eats something toxic?

Do not panic, but do act.

Remove access

Stop your dog eating any more if you can do so safely.

Keep the packaging

If possible, keep the:

• wrapper
• ingredient list
• box
• bottle
• remaining food

A photograph can also help.

Work out roughly what happened.

Try to establish:

• what was eaten
• approximately how much
• when it happened
• your dog’s approximate weight

Contact a professional

Contact your veterinary practice.

You can also use Animal PoisonLine in the UK for specialist poisoning advice.

If your dog has collapsed, is having seizures, has difficulty breathing or is seriously unwell, contact a vet immediately rather than delaying treatment.

Do not make your dog vomit.

Never use:

• salt water
• hydrogen peroxide
• mustard
• oil
• fingers down the throat

unless a veterinary professional has specifically instructed you to take an appropriate action.

My Dog Poisoning guide covers emergency poisoning response in much greater detail.

Should I call my vet even if my dog looks normal?

Yes, if they have eaten something known or suspected to be toxic.

Some toxic effects are delayed.

With allium poisoning, for example, red-blood-cell damage may not become obvious immediately. Grape toxicity may also progress before an owner sees dramatic symptoms.

That is why I do not recommend waiting for a list of symptoms before seeking advice.

How I try to prevent food problems when caring for dogs

Food safety matters when somebody else is responsible for your dog too.

When I am house sitting or caring for a dog, I follow the owner’s agreed feeding instructions rather than adding foods because I think the dog might like them.

I also want to know about:

• allergies
• food intolerances
• veterinary diets
• medications that need to be given with food
• foods the dog must avoid
• scavenging habits
• previous incidents

Consistency becomes particularly important when a dog has dietary restrictions.

My pet and house sitting service focuses on maintaining the pet’s normal routine rather than changing it while the owner is away.

Dogs can find toxic food on walks too

Food poisoning risks do not stop at the front door.

On local walks I pay attention around:

• bins
• picnic areas
• benches
• takeaway shops
• discarded shopping
• barbecue areas
• food dropped near playgrounds
• rubbish bags

Common finds can include chicken bones, chocolate, chewing gum, grapes, mouldy food and unknown leftovers.

Management matters.

For a dog who scavenges, I would rather prevent access and use reward-based training than repeatedly test whether they will ignore something dangerous.

Teach a useful leave and drop.

Training cannot guarantee that a dog will never pick up something unsafe.

But a well-practised leave and drop can be extremely useful.

I prefer teaching these with rewards rather than chasing the dog or forcibly taking things from their mouth.

Chasing can turn scavenging into a game.

For dogs who repeatedly swallow dangerous objects, a properly introduced basket muzzle can also form part of a sensible safety plan alongside reward-based training.

Frequently asked questions

What are the most important toxic foods for dogs?

Important examples include chocolate, grapes, raisins, sultanas, currants, onions, garlic, leeks, chives, xylitol, alcohol, caffeine and macadamia nuts.

Mouldy food and uncooked bread dough can also be dangerous.

Can dogs eat garlic?

I do not recommend deliberately feeding garlic as a health supplement or flea treatment.

Garlic belongs to the allium family alongside onion, leeks, shallots and chives, and veterinary poisoning guidance recognises alliums as potentially toxic to dogs. (Animal PoisonLine)

My dog ate one grape. Do I really need to call a vet?

Yes.

There is no reliable way to predict which dog will develop grape toxicity or exactly what dose will cause problems. Contact your veterinary practice or Animal PoisonLine.

Is avocado poisonous to dogs?

Avocado is not as straightforward as grapes or xylitol. Dogs are comparatively resistant to persin, but avocado is high in fat, and the stone can cause choking or obstruction. I would choose safer treats instead.

Can dogs eat bacon?

Bacon is not normally classified as a dog poison.

However, it is salty and fatty, so I don’t recommend it as a regular dog treat.

That is different from saying bacon is “toxic”.

Are cooked bones poisonous?

No, but that does not make them safe.

Cooked bones can splinter, cause injuries, become lodged or create a gastrointestinal obstruction.

What should I do if my dog eats chocolate?

Keep the wrapper if possible and contact your veterinary practice promptly. Tell them the type of chocolate, amount eaten, approximate time and your dog’s weight.

Do not wait until symptoms develop.

Can I give salt water to make my dog sick?

No.

Do not attempt to make your dog vomit at home unless a veterinary professional specifically instructs you. Salt water can itself cause poisoning.

What is Animal PoisonLine?

Animal PoisonLine is a UK specialist telephone service for owners concerned that a pet has been exposed to something poisonous.

The Veterinary Poisons Information Service runs it and charges for calls.

If your dog is already seriously unwell, contact your vet immediately.

Related dog food, health and safety guides

For everyday feeding decisions, start with my Dog Food & Nutrition Guide.

If your dog has already eaten something potentially harmful, use Dog Poisoning: What to Do If Your Dog Eats Something Toxic.

For wider emergency preparation, visit my Dog Health & First Aid guide.

For fruit specifically, see Safe Fruits for Dogs.

You may also find How to Choose the Right Dog Treats useful.

Related Guides

• Chocolate and Dogs – What to Do If They Eat Chocolate
• Dog Poisoning: What to Do If Your Dog Eats Something Toxic
• Dogs and picnics: summer safety tips
• Can Dogs Eat Garlic? A Practical Guide for Dog Owners
• Rock Salt / Grit

Veterinary and nutrition disclaimer

I am a professional dog walker with canine first-aid training. I am not a veterinary surgeon or veterinary nutritionist.

This page provides general information about foods that may be harmful to dogs. It is not intended to calculate a toxic dose, diagnose poisoning or replace veterinary advice.

If you think your dog has eaten something potentially toxic, contact a veterinary professional promptly. Do not wait for symptoms and do not try to make your dog vomit unless specifically instructed by a veterinary professional.