5 Poisonous foods your dog should avoid

Although they are tempting to a dog, there are a number of poisonous foods our dogs must avoid.


Dogs have a fabulous sense of smell and a wonderful, curious nature. As you probably know, dogs are quite keen on eating just about anything sometimes, and will pick up all sorts of things they shouldn’t. The risks are that there are some foods that are quite poisonous to dogs and can lead to serious health complications, some of which are fatal. Puppies are especially curious, but dogs of all ages can be at risk from foods that are toxic.
Although they are tempting to a dog, there are a number of poisonous foods our dogs must avoid. Here are five you should know about:


  1. Grapes and raisins

Although they are a healthy treat for humans, grapes and raisins should not be fed to dogs. Even the smallest amount can be fatal to our furry friends.

Recent studies have shown that grapes and raisins (and all varieties of the Vitis species) can cause kidney failure in dogs. The reasons why are not fully understood, and anecdotal evidence suggest that the amount required to create a problem can vary a great deal. However many cases of ‘poisoning’ by grapes and raisins have been reported involving dogs and the number of cases is rising.

The general consensus at present is that potentially any dose should be considered a problem. Estimated amounts of grapes associated with renal injury in dogs are about 32 g/kg; amounts of raisins associated with signs start at 11 g/kg. So even an amount below a small handful of raisins can be quite dangerous.

Vomiting and diarrhoea are often the first signs of grape or raisin poisoning. The symptoms often develop within a few hours of ingestion. Further symptoms include weakness, loss of appetite, increased drinking, and abdominal pain. Acute kidney failure develops within 48 hours of ingestion.

Along with all varieties of the grape family to avoid, such as grapes, raisins and currants, food containing grapes and raisins, such as biscuits, cakes or muesli can still be potentially poisonous to dogs.

  1. Chocolate

Many dogs love chocolate, and like other potentially dangerous foods, a dog will not know whether the tasty treat you are eating yourself is good or bad for the dog!

The roasted seeds of the cocoa tree (Theobroma cacao) contain both caffeine and theobromine which, when ingested by dogs, can lead to serious medical complications. Even a small amount of chocolate can give your dog an upset stomach, with symptoms including vomiting or diarrhoea.

With larger amounts, the theobromine in chocolate can produce muscle tremors, seizures, an irregular heartbeat, internal bleeding or a heart attack. The onset of theobromine poisoning is marked by severe hyperactivity, restlessness and excitement.

If eaten in a large enough quantity, chocolate can prove to be fatal to a dog.

According to the RSPCA, cocoa powder, baking chocolate and dark chocolate contain higher levels of theobromine compared to milk chocolate.

If your dog eats a small amount of chocolate, symptoms may not be noticeable. However, the more that is eaten, the higher the chances are that your dog may be poisoned. The main effects of theobromine poisoning occur on the dog’s central nervous system.

The milder symptoms of theobromine ingestion may include:

  • Restlessness
  • Excitement
  • Hyperactivity
  • Nervousness
  • Trembling

Higher doses may cause the dog to become agitated. Beyond that the symptoms that may be:

  • Vomiting
  • diarrhoea
  • increased drinking and increased urination
  • increased heart rate
  • muscle tremors
  • seizures, even coma and death can result.

Puppies and smaller dogs may be affected by smaller amounts of chocolate.


3. Tomato

The tomato is part of the Solanaceae or nightshade family which includes potatoes, pepper and eggplants. The tomato is considered toxic to dogs when green (as is the potato) with the immature and not yet ripened fruit, leaves, and stems containing the highest concentrations of toxin.

As the fruit ripens, the tomatine toxin lessens, so ripe tomatoes become much safer than green tomatoes.
The signs of tomatine poisoning in dogs include:

  • lethargy
  • drooling and increased salivation
  • difficulty breathing
  • loss of appetite
  • vomiting, diarrhoea or constipation
  • widely-dilated pupils

More severe symptoms include:

  • paralysis
  • cardiac effects
  • central nervous effects such as muscle weakness, tremors, seizures
  • coma and death

Dogs can enjoy cooked potato in moderation – like tomatoes, it is the green parts which contain toxins and should be avoided.

  1. Mushrooms

Among the plants found in your backyards that could make your dog sick, some are highly toxic, while others may just result in mild stomach upset. As with humans, although some mushrooms are fine to eat, others can have both mild and more serious effects.

Because it can sometimes be difficult to confirm which type of mushroom your dog may have eaten, if your dog becomes ill it is best to try and take some of the suspected mushroom with you when taking your dog to the vet.

Mushrooms do qualify as a food which can be dangerous for your dog to eat. If you do have mushrooms growing in your yard or garden it is best to dig them out and dispose of them, to minimise the availability to your dog while they are outside and possibly unsupervised.

But don’t worry too much if your dog eats a bit of your mushroom omelette, for example, as field mushrooms are considered ok in small quantities for your dog to eat.

But Boletus mushrooms, such as porcini, for example, although edible for both us and our canine friends, can cause gastro-intestinal upset for your dog.

It really comes down to helping your dog avoid eating any mushrooms for their health.

Mushroom poisoning in your dog could result in:

  • Nausea and abdominal pain
  • Diarrhoea or vomiting
  • Weakness and Lethargy
  • Seizures or convulsions
  • Unconsciousness
  • Excessive drooling
  • Uncoordinated motor skills and
  • Coma and possibly death

Symptoms will vary depending on the amount and type or mushroom consumed. If possible, and you need to take your dog to the vet, try and take some of the suspected mushroom with you to assist in identifying the risks to your dog’s health.

  1. Avocado

Avocado may be an excellent superfood for humans, but the avocado contains the chemical called Persin, in all parts of the fruit – stem, seed, skin and flesh, which is risky for a dog to ingest.

Government advice shows that avocado ingestion by dogs can cause the following effects:

  • gastrointestinal irritation
  • vomiting
  • diarrhoea
  • respiratory distress
  • congestion
  • fluid accumulation around the tissues of the heart and even


It isn’t known exactly how much avocado needs to be eaten by a dog in order for these effects to be seen. And scientists don’t yet know why avocado affects dogs as it does. We do know that the higher fat content of avocados can cause the gastrointestinal effects shown above.

Other reported problems with Avocados have related to their fat content.  In these cases the problems seen were stomach upset, vomiting and pancreatitis.


Although advice states that only certain types of avocado are problematic to dogs, the specifics vary, so perhaps it is best to avoid feeding avocado to your pet Fido



FinallyThe RSPCA have a site with help on food your dog shouldn’t eat.

Here’s a list of foods that dogs should avoid…this is not a complete list: onions or onion powder, garlic, chocolate, coffee or caffeine products, mouldy or spoiled foods or compost, avocado, bread dough, yeast dough, grapes, raisins, sultanas (Christmas cakes etc), currants, nuts including macadamia nuts, fruit stones (pits) or fruit seeds, corncobs; green unripe tomatoes, mushrooms; fish constantly, cooked bones; small pieces of raw bone, fatty trimmings/ fatty foods, Salt,  Xylitol (sugar substitute found in some products such as some types of sugar-free chewing gum, lollies, baking goods, toothpaste).

Please get help from a vetarinarian if there is any indication your pet has ingested the foods in this list. Immediate action should be taken to reduce the amount of damage. Before you do anything, consult your veterinarian. Let them know what your dog ate, the amount, and when it occurred. Getting help as soon as possible might make the difference in a life and death situation.