What can dogs not eat? 25 toxic foods for dogs

Updated March 30, 2026

As a responsible pet parent or sitter, it’s vital you’re up to speed on what dogs can’t eat. Feed your canine companion the wrong food and they could suffer from a variety of health issues including gastrointestinal distress, anemia, kidney failure and so much more.

To make sure you never feed a dog something that could cause health issues and death in some cases, explore these 25 toxic foods for dogs below.

25 toxic foods for dogs 

Whether you’re a pet parent, sitter or a friend of dog owners, it’s important to never feed a dog something that could cause harm. Feeding a food toxic to dogs could cause a variety of health complications, such as seizures, abnormal blood pressure and in the worst cases, death. 

So without any further ado, take note of our list of poisonous foods for dogs.

1. Xylitol
2. Grapes
3. Avocado
4. Onions
5. Caffeine
6. Garlic
7. Macadamia nuts
8. Chocolate
9. Bones
10. Fruit seeds and pits
11. Salt
12. Ice cream
13. Lemon
14. Lime 
15. Rhubarb
16. Green tomatoes
17. Raisins
18. Marshmallows
19. Cherries
20. Nutmeg
21. Raw yeast dough
22. Moldy food
23. Some nut butters
24. Alcohol
25. Corn cob

Xylitol 

Xylitol is a sugar substitute and is found in popular treats such as gum, sugar-free candy, and many brands of peanut butter. Xylitol is an extremely toxic ingredient for dogs, and can cause low blood sugar and liver failure, resulting in symptoms such as weakness, seizures and coma. 

Grapes

Grapes are highly toxic to dogs and even eating just one could result in vomiting, diarrhea, loss of appetite and eventually kidney failure in dogs.

Avocado

Avocado is a food for dogs to avoid because it contains a toxin called persin, and can cause vomiting, diarrhea, and in severe cases it has been known to damage the heart.

Onions

Onions are highly poisonous to dogs because they contain a compound called N-propyl disulphide which - when ingested - breaks down red blood cells which leads to anemia. In the worst cases, ingestion of onions in dogs can result in death. For this reason, onions in any form (including the small amounts found in many foods and sauces) should be avoided at all costs.

Caffeine

Coffee and other caffeinated drinks including black, white and green tea, as well as many energy drinks, are very dangerous and toxic to dogs.

Compared to humans, dogs are much more sensitive to the stimulating effects of caffeine. Therefore, even small amounts of caffeine can cause a variety of symptoms. These range from vomiting and diarrhea to a loss of muscle control, tremors, seizures, raised blood pressure and cardiac arrhythmias. 

Garlic

Garlic is one of the most toxic foods for dogs, along with all other members of the allium family, including chives and leeks.

Garlic contains a compound called thiosulfate, which damages red blood cells and can lead to anemia, along with vomiting, diarrhea and abdominal pain. 

Even a tiny amount of garlic could be life-threatening, so never feed your dog anything containing it (or any other allium).

Macadamia nuts

Macadamia nuts are highly toxic to dogs and can cause serious - even fatal - reactions, and signs include muscle shakes and ataxia, vomiting, and panting. So with that in mind, definitely save macadamia nuts on your list of foods you should not feed a dog.

Chocolate

Chocolate is one of the most toxic foods for dogs because it contains a compound called theobromine, with the highest concentration being in dark chocolate.

Ingestion of chocolate can cause vomiting and diarrhea, a high heart rate, tremors and even death in dogs, so contact your veterinary clinic as soon as possible if your dog has eaten even a small amount. Keeping the original packaging will also help your vet calculate the amount of theobromine your dog has ingested.

Chocolates containing milk could also give your dog an upset stomach, because many dogs are sensitive to milk and other dairy products.

Bones

Although bones were traditionally seen as suitable for dogs to eat, it is highly recommended not to feed any dogs any bones, regardless of whether they are raw, frozen, or cooked. 

This includes bones from chicken, pork, beef, lamb, and any other animal species. Feeding items such as beef and pork knuckles and antlers are also not recommended. Any item that is too hard for you to make a dent in with your fingernail, without bending your fingernail, is best avoided.

Raw bones can also house harmful bacteria like salmonella, which can cause vomiting and diarrhea in dogs. 

Cooked bones easily splinter which can puncture your dog’s gastrointestinal tract, causing internal injury and very serious complications.

So, if you want to know - what can dogs not eat - add bones of all kinds to your list.

Fruit seeds and pits

Pitted fruits such as peaches, nectarines, and cherries contain cyanide, which can be toxic to dogs if ingested in large quantities. The potential symptoms of cyanide toxicity include increased salivation, cherry red gums, dizziness, convulsions, and difficulty (or rapid) breathing. Some pits also have rough edges which can damage the espohagus, pose a choking risk, or cause a dangerous blockage if consumed.

Salt

Too much salt could result in excessive dehydration in dogs or even lead to sodium ion poisoning. Possible symptoms of sodium ion poisoning are vomiting, diarrhea, tremors, seizures, or in the worst case, death.

So if you’re wondering - what can dogs not eat amongst our human foods, foods packed with salt like potato chips and salted peanuts should be avoided.

Ice cream

If you’re wondering - what food is bad for dogs that we humans eat - ice cream should be at the top of your list.

Ice cream is a people food - not a dog food - for many reasons. Ice cream contains large amounts of fat and sugar, and often xylitol - a sweetener that is highly toxic to dogs.

It’s also amongst the foods dogs should not eat because it's often dairy-based, and many dogs are lactose intolerant.

Lemon

Lemon is amongst the foods toxic to dogs because it contains high levels of citric acid which can cause vomiting and diarrhea in dogs.

Lemon skin and rind also contain a compound called psoralen, which may cause skin and eye sensitivity to light.

Lemons also contain limonene, which can cause damage to a dog’s liver if ingested.

Lime

Lime should be on your list of harmful foods for dogs because, like lemons, it contains high levels of citric acid, which in high enough quantities can result in loss of coordination and central nervous system depression in dogs. 

Lime also contains the essential oils linalool and d-limonene which can lead to liver damage and potentially liver failure in dogs.

Rhubarb

Rhubarb should be on your list of foods toxic to dogs because it contains calcium oxalate, which can…

• cause gastrointestinal irritation;
• bind to the calcium in the blood, which removes calcium from the system and damages the kidneys;
• crystalize in the urine and form bladder stones.

Green tomatoes 

If you’re wondering - what fruit is bad for dogs - it’s green tomatoes. They contain high levels of the compounds solanine and tomatine, which can irritate the gastrointestinal tract to cause vomiting and diarrhea. If larger quantities are ingested they can also cause drowsiness, confusion, abnormal heart rate and changes in behavior.

Ripe red tomatoes are considered safe for dogs, but only feed as an occasional treat.

Raisins

Raisins - as well as their close relatives, sultanas and currants - are one of the human foods dogs should never eat. Ingesting just one piece of these dried fruits has the potential to cause fatal kidney damage, vomiting, diarrhea, dehydration, and a variety of neurological symptoms such as head tilt, muscle tremors and seizures. For this reason, it’s also essential to check that any food you feed your dog does not contain any hidden pieces of dried fruit! 

Marshmallows

Marshmallows can be toxic to dogs because they often contain xylitol - a sweetener that can cause liver failure and seizures in dogs. 

It’s also a bad human food for dogs because it contains no nutritional value for them, is often high in sugar and fat, and poses a choking hazard.

Cherries

Cherries should be on your list of foods poisonous to dogs because the pit, stem and leaves contain cyanide, which can result in cyanide poisoning in dogs. Symptoms of this include increased heart rate, muscle spasms, seizures, bright red gums, drooling, vomiting and rapid breathing.

So, if you want to know what foods are deadly to dogs, cherries should be on your list.

Nutmeg

Nutmeg is considered a toxic substance for dogs because it contains myristicin, which is a hallucinogenic compound.

If a dog ingests nutmeg, they could suffer from stomach upset, increased heart rate, convulsions, hallucinations, breathing issues and disorientation.

Whilst the small quantities of nutmeg added into most recipes are unlikely to cause your dog serious harm, it is always better to avoid it than take the risk.

Raw yeast dough

Never feed your dog raw yeast dough because as yeast ferments, it produces ethanol (alcohol) and carbon dioxide. The fermentation process can continue once ingested, which can lead to bloating and difficulty walking.   

The alcohol can also lead to alcohol poisoning in dogs, which can cause nausea, vomiting, low blood sugar and low body temperature.

Moldy food

Moldy foods are not safe for dogs to eat because they can contain harmful mycotoxins. Common symptoms are seizures, tremors, increased body temperature, disorientation, and death.

Some nut butters

Many nut butters contain the sweetener xylitol, which is toxic to dogs and should never be consumed.

Many also contain additional salt and sugar, which is unhealthy for dogs to consume.

Some nut butters - like one-ingredient peanut butters are safe for dogs, but always check the label.

Alcohol

Dogs should never consume alcohol - it could result in alcohol poisoning in dogs and damage to the central nervous system.

Corn cob

While dogs can have small amounts of sweetcorn as a treat, they should never be given the cob - ingestion not only poses a choking hazard, but it can also result in lethargy, vomiting, diarrhea and reduced appetite. It is also at high risk of causing an intestinal blockage, which can be life-threatening.

Tips for ensuring dogs avoid toxic foods

• Keep foods in cupboards, out of your dog’s reach
• Don’t leave empty packets around
• Don’t leave dirty dishes around
• Always check the label for toxic ingredients
• Secure a trusted dog sitter

While you can control what your dog eats while they’re in your care, it’s worth considering what you’ll do with your pooch while you’re on vacation. 

One option is to welcome an experienced dog sitter who knows exactly what dogs can and can’t eat. Take a look below to find out how to find verified dog sitters.

Considerations for pet sitters

As a pet sitter, it’s vital you’re clued-up on what dogs can and can’t eat, and you should always follow the pet parents’ instructions on what to feed the dogs in your care.

If you’re feeling prepared for taking care of a pooch and the idea of pet sitting in exchange for worldwide stays calls your name, take a look below to find out how to secure a dog sit.

Meet our veterinary expert, Liam

This article has been checked by veterinarian Dr Liam Bullock BVSc (Hons) MRCVS.

As a small animal vet, Liam has spent time working in both first-opinion and referral-level practices. After gaining a strong affinity for educating owners about their pets, Liam decided to dedicate some of his non-clinical time to tutoring students, who were preparing for exams or struggling at school. By combining a passion for teaching others, and a keen interest in raising awareness about animal health issues, Liam decided to begin writing veterinary content. This now also allows him to raise awareness of important animal health issues outside of the consultation room.

Useful resources

• Can dogs eat barbecue?
• Can dogs eat salmon?
• Can dogs eat dates?