
Pet owners always want to ensure their animals’ well-being and health. While it’s tempting to share our food with them, certain human foods, fruits and vegetables can be harmful and toxic to animals. In this article, you will find a complete list of 26 foods that dogs can’t eat. You will also learn how to safeguard your pets from these harmful foods, as well as what foods that you are growing in your polytunnel should be kept away from pets.
Before we start, make sure to learn about what should and shouldn’t be grown in a polytunnel.
Table of Contents
What Fruits Can Dogs Not Eat
There is a clear reason why dogs are carnivores, because many fruits, vegetables, and other foods that we are about to discuss are harmful to them.
For instance, there are numerous fruits that are toxic or harmful to dogs. Here are the main ones to avoid feeding to your dogs at all costs when understanding foods that dogs can’t eat:
1. Grapes and Raisins:

These seemingly innocent fruits can be incredibly dangerous for dogs. Even a small amount of grapes or raisins can lead to irreversible kidney damage and failure, which can progress fast, depending on the size of your dog. If you suspect your dog has consumed either of these, consult your vet immediately.
2. Avocados:

Whilst avocados are not usually considered as harmful to dogs as grapes and raisins, we still recommend that you avoid feeding your dog these. The skin and stone contained within an avocado are the most harmful components to dogs, since they contain a toxin called Persin, which, although harmless to humans, can cause breathing problems, sickness, and diarrhoea in pets.
3. Unripe Tomatoes:

While fully ripe red tomatoes are generally safe for dogs, tomato plants and unripe tomatoes can be harmful. Tomatoes contain tomatine, a chemical which can potentially damage the nervous system, kidneys, and digestive tract. If you’re growing tomatoes, ensure that your dog or other household pets can’t access them.
4. Rhubarb:

Another fruit bad for dogs is rhubarb, which is also harmful for chickens too. The leaves, in particular, are dangerous, as they can cause damage to the nervous system. Symptoms of rhubarb poisoning in dogs include tremors, seizures, and heart problems. If you suspect your dog has eaten rhubarb, consult your vet straightaway.
What Vegetables Can Dogs Not Eat
Next, as well as what fruits dogs can’t eat, we have to consider what vegetables dogs can’t eat. This section will also be helpful when learning about what vegetables to not grow in polytunnels.
5. Potatoes:

Raw potatoes are the one the worst vegetables that dogs cannot eat, because they contain a toxin called Solanine. This toxin can result in various complaints, including diarrhoea, vomiting, and confusion. While cooking potatoes will reduce Solanine levels, boiling them doesn’t eliminate it entirely. Moreover, potatoes are usually prepared with added salt and fats, which are also harmful to dogs. It’s best to avoid feeding dogs any form of potatoes.
6. Broccoli:

Another vegetable that is harmful to dogs is broccoli. Some may also wonder if dogs can eat broccoli. Whilst there are many nutritional benefits of broccoli for humans, chemicals within broccoli can irritate their stomachs. To an extent, dogs can eat broccoli, but only in specified amounts when prepared appropriately for each breed.
7. Onions, Chives, and Garlic:

In very small quantities, garlic can actually be beneficial for your dog. However, excessive consumption of garlic, onions, or chives can lead to harm and damage your dog’s red blood cells. Whether it’s raw, cooked, or dried, avoid feeding your dog either of these vegetables.
8. Corn on the Cob:

Dogs can easily digest, but this can lead to complications such as blockages in their intestines, which is a severe health risk. Therefore, do not feed your dog corn on the cob.
9. Mushrooms:

Ordinary mushrooms used in cooking are generally safe for dogs. However, wild mushrooms can be highly poisonous to humans as well as dogs here. Even when you are walking your dog, be aware of wild mushrooms appearing on your travels, as dogs may be tempted to eat them. Dogs can be affected by various mushrooms differently, but the main symptoms include diarrhoea, vomiting, and restlessness.
Seeds and Nuts Toxic To Dogs
As well as fruits and vegetables that are toxic to dogs, we also have to consider seeds and nuts. In this next section, you will learn about what seeds and nuts are toxic to dogs, and what hazards they can cause to them.
10. Pips, Seeds, and Stones:
As tempting as it may be to toss your dog an apple core or a cherry pit, you should resist the urge completely. The pips, seeds, and stones from various fruits (such as the aforementioned avocado) contain small amounts of cyanide, which can be extremely harmful and even fatal to your dog. Fruits such as these should be avoided:
- Apples.
- Cherries.
- Plums.
- Peaches.
11. Macadamia Nuts:
Macadamia nuts contain a toxin that can affect your dog’s muscles and nervous system, leading to symptoms such as weakness, swollen limbs, and panting. Whilst this toxin is unknown, you should still be aware about macadamia nut poisoning in dogs.
12. Nuts:
As mentioned, dogs should not consume nuts, as they do not contain the same benefits for canines as it does for humans. Even non-poisonous nuts can be difficult to digest for dogs and may cause other health problems too. Therefore, keep all nuts out of your dog’s reach, as well as these too:
- Walnuts.
- Pecan nuts,.
- Nut butters (e.g., peanut butter)
13. Persimmon Seeds:
Although persimmons are not common in the UK, they are an exotic fruit that can be purchased in some supermarkets. Again, permission seeds can be very harmful to dogs. Ingesting persimmon seeds can result in blockages, diarrhoea, and a high temperature.
What Should I Do If My Dog Has Eaten Any of These?

If your dog has consumed any of these toxic seeds, nuts, or substances, even in small amounts, consult your vet straightaway. If not, what at first may be a small concern can quickly become fatal.
Smaller Toxic Foods
Aside from fruits, veg, and nuts toxic to dogs, there are additional foods that humans may consume that dogs can’t eat.
14. Cherry Pits:
Cherry pits, like many other fruit pits, contain cyanide and should never be given to dogs.
15. Candy:
Candy often contains sugar and artificial sweeteners that can be harmful to dogs, especially those containing Xylitol.
16. Chewing Gum:
Chewing gum can also contain Xylitol which is harmful to dogs, and can lead to hypoglycemia, liver failure, and blood clotting disorders.
17. Salt:
Previously, we have highlighted certain fruits, vegetables, and nuts high in salt that are harmful to dogs, such as potatoes. After all, excessive salt intake can lead to salt poisoning in dogs, resulting in symptoms like vomiting, diarrhoea, and even seizures.
18. Yeast Dough:
Yeast dough can expand in a dog’s stomach, causing discomfort and potentially leading to bloating.
19. Cooked Bones:
While raw uncooked bones can be suitable for dogs to chew on, cooked bones are a different story. They can easily splinter, causing constipation or, in severe cases, perforation of the gut, which can be fatal to dogs.
20. Raw/Undercooked Meat, Eggs, and Bones:
You may think, as canines, that raw meat wouldn’t be toxic to dogs. However, raw meat and eggs contain salmonella bacteria and E. coli, which is harmful to dogs, humans, and other pets. Additionally, raw eggs contain avidin, an enzyme that can affect biotin absorption, potentially leading to skin and coat problems. Therefore, do not underestimate these foods that are toxic to dogs.
21. Coconut and Coconut Oil:
In small amounts, fresh coconut and coconut-based products are generally not harmful to dogs. However, the oils in coconut can lead to stomach upset, loose stools, or diarrhoea. Coconut water, high in potassium, should be avoided as well.
Beverages Poisonous to Dogs
We believe that it is also worth knowing about what drinks and other beverages are harmful to dogs as well as foods.
22. Alcohol:
Alcohol can have more severe effects in dogs than in humans, and can lead to symptoms such as sickness, diarrhoea, and damage to the central nervous system.
23. Tea:
Tea contains caffeine, which can be harmful to dogs. Caffeine can lead to restlessness, rapid breathing, and even seizures in some cases. Avoid letting your dog consume tea.
24. Hops:
Hops are flowers that are used to brew beer, and can be extremely toxic to dogs. If your dog consumes hops, this can lead to a rapid heart rate, elevated body temperature, and seizures.
25. Chocolate, Coffee, and Caffeine:
These popular products all contain substances known as methylxanthines. These compounds are found in cacao seeds, coffee beans, and certain soda extracts. When pets ingest methylxanthines, it can result in vomiting, diarrhoea, panting, excessive thirst and urination, hyperactivity, abnormal heart rhythm, tremors, seizures, and even death.
Furthermore, dark chocolate is more dangerous than milk chocolate, while white chocolate surprisingly has the lowest risk to animals, although this should still be avoided. Baking chocolate contains the highest levels of methylxanthines.
26. Milk and Dairy:
Lastly, we have to consider milk and other dairy products. Whilst we have already touched on coffee, tea, and chocolate which widely contains milk, these should all be kept away from dogs. Many dogs, like some humans, are lactose intolerant, lacking significant amounts of lactase, the enzyme needed to break down lactose in milk, and can lead to upsetting the tummy, and diarrhoea.
Poisonous Plants To Dogs

Its also necessary to be aware of potentially poisonous plants that could pose a threat to your dog and other household pets. Previously, we mentioned mushrooms, but here are other plants to watch out for when walking your dog that they should stay away from:
- Lilies
- Oleander
- Azaleas
- Autumn Crocus
- Castor Bean Plant
- Daffodils
- Sago Palm
- Tulips
- Foxglove
- Yew
These plants can cause a range of reactions, from mild nausea to severe illness or even death in certain animal species. Cats, in particular, are known to be highly sensitive to the effects of some toxic plants, such as lilies.
Fruit and Veg Grown In Polytunnels That Dogs Can’t Eat
When it comes to fruits and vegetables grown in polytunnels, it’s important to apply the same caution as you would with outdoor crops. If you are growing any of the fruits or vegetables listed this article in your domestic polytunnel, be sure to keep your dog away from them. As well as this, we have some great advice about running a livestock polytunnel, and keeping chickens in the garden to consider alongside this advice on what foods that dogs can’t eat.
Protect Your House Pets Against Toxic Foods
In conclusion, knowing what fruits and veg dogs can’t eat is optimal to maintain their welfare and protection from potential healthcare issues. Whilst in some instances, dogs can eat fruit, but this should only be in small quantities, and ultimately, being aware of these toxic foods for dogs will help you to make the right choices when feeding your pets, as well as when on walks. Make sure to remind yourself of dog poisoning signs and symptoms for further details.
FAQs
Are bananas considered foods that dogs can’t eat?
No, bananas are not bad for dogs in moderation. They can be a healthy and occasional treat for dogs. Bananas are a good source of vitamins, minerals, and fibre. However, because they are relatively high in sugar, it’s important to feed them to your dog in small amounts. Too many bananas can lead to digestive upset or weight gain. Always remove the peel before offering a banana to your dog.
Is it bad for dogs to eat cheese?
Cheese is not inherently bad for dogs, but it should be given in moderation. Many dogs enjoy the taste of cheese, and it can be used as an occasional treat or training reward. However, some dogs may be lactose intolerant, so cheese can cause digestive issues like diarrhoea or upset stomach in such cases. Choose low-fat, low-sodium cheeses and offer them in small amounts as part of a balanced diet.
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Sean Barker is the MD of First Tunnels, and is enthusiastic about providing quality gardening supplies to gardeners across the UK