Foods that are Potentially Toxic to Dogs 2017-03-19T16:13:52+00:00

Some common foods can be poisonous to dogs and puppies, sometimes in very small amounts. It should not be assumed that human food is safe for your dog.

The food items listed below should not be given to dogs and should be stored safely out of their reach. Care should also be taken when preparing and serving these foods for human consumption to ensure your dog is not tempted to clean up after you.

  • Grapes/Raisins
  • Chocolate
  • Coffee Grounds/Beans and Tea (Caffeine)
  • Onions
  • Macadamia Nuts

Grapes and Raisins

Grapes and raisins contain an unknown toxin which can cause kidney failure in dogs. Please be aware that raisins are more concentrated than grapes, hence more toxic. The toxic dose has not yet been determined. Eating just a handful of raisins and grapes has been shown to cause kidney failure, whereas in other cases large quantities have been consumed without ill effect. It is recommended that the feeding of grapes and raisins is avoided completely.


Chocolate contains Theobromine. Thebromine and caffeine stimulate the heart and nervous system. Dogs (and cats) are more sensitive than humans to the effects of these substances. In dogs these substances can cause seizures, coma and death occurring from heart failure.  Plain and dark chocolate contains more Theobromine and therefore is more dangerous than milk chocolate if your dog ingests it. Theobromine remains in the dogs system for a long time, meaning that chocolate poisoning can occur if small amounts of chocolate are fed repeatedly.

Please remember that cocoa powder, baking chocolate and other foods contain Theobromine.

It has also been reported that Cocoa husk mulch (sold in garden centres) is highly toxic.

Dog chocolate has had the Theobromine removed.

Coffee Grounds/Beans and Tea (Caffeine): Coffee granules/beans and tea contain caffeine. The symptoms of coffee poisoning are similar to the symptoms of chocolate poisoning.


Onions contain Thiosulphate a substance, which can cause the destruction of red blood cells (haemolytic anaemia) and potentially life-threatening anaemia. Thiosulphate levels are not affected by cooking or processing. Raw or cooked onions, onion powder and shallots can all cause toxicity.

Occasional exposure to small amounts is usually not a problem, but continuous exposure to even very small amounts can be a serious threat.

Macadamia Nuts

Macadamia nuts (raw and roasted) can cause dogs to develop a tremor of the skeletal muscles, and weakness or paralysis of the hindquarters. The exact substance that triggers the reaction is unknown as is the toxic dose although it is thought to be very small. This is currently known as toxic only to dogs.

Some other foods which should be avoided:

Seeds and or stones from:  Apples, Apricots, Cherries, Peaches and Plums:

The fruits themselves are not considered toxic; however the seeds/stones contain a type of cyanide compound which can poison your dog if enough of them are eaten.

Alcohol: Dogs are susceptible to alcohol poisoning. If enough alcohol is ingested, it can cause death.

Animal fat, fried and fatty foods: Excessive fat can cause pancreatitis.

Avocados: The fruit, leaves, stem and pit are all toxic. The toxic substance is called Persin (a fatty acid derivative). Ingestion of the Avocado plant can cause difficulty breathing, fluid accumulation around the heart, vomiting, diarrhea generalised congestion, and heart failure. Currently the amount of avocado fruit or other parts of the plant, needed to poison your dog is unknown.

Broccoli: If fed in very large quantities (i.e. over 10% of the dog’s diet) Broccoli can be toxic causing intestinal irritation. 

Hops: Can cause malignant hyperthermia in dogs, usually with fatal results.  Certain breeds, such as Greyhounds, seem more sensitive to hop toxicity, but hops should be kept away from all dogs. Even small amounts of hops can trigger a potentially deadly reaction.

Nutmeg: High levels of nutmeg can result in seizures, tremors, central nervous system problems, and even death.

Rhubarb Leaves: Large amounts of raw or cooked rhubarb leaves can cause convulsions, coma and in extreme cases, death.

Salt: Excessive salt intake may cause kidney problems. Salt should never be given to a pet to induce vomiting; increased sodium content in the blood causes the brain cells to swell (cerebral oedema). Never add salt to the ingredients of the treats and do not feed foods with high salt content to your dog; e.g. Bovril or gravy granules.

Tomatoes: Contain atropine, which can cause dilated pupils, tremors, and heart arrhythmias. The highest concentration of atropine is found in the leaves and stems of tomato plants.

Uncooked Yeast Dough/Bread Dough: Expands and produces gas in the digestive system, causing pain and possible rupture of the stomach or intestines. Rising dough can also release ethanol, enough to cause alcohol poisoning.

Obviously these foods are not the only potential hazardous substances found in the home and garden. Fertilizers, slug pellets, cleaning agents, antifreeze, detergents, mouse/rat poison, moth balls, vitamins, some garden/house plants and many types of medication can all be extremely dangerous to pets. It is common sense to ensure that these items are properly stored away from your pets.

There are many plants that are poisonous to dogs that may be in your garden please visit the site below to familiarise yourself with these plants.  This list is not exhaustive and is purely for information.

If your dog shows any sign of illness, please contact your Veterinary Surgeon for advice immediately