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Dangerous foods - macadamia nuts and artificial sweeteners

We all like to treat our dogs and cats to the odd bit (or more) of human foods, but be aware quite a few of our favourite foods are not meant for consumption by dogs (and sometimes cats). As with chocolate, onions, grapes and raisins, the following foodstuffs are frequently dangerous – if not fatal – when fed to dogs.

Macadamia nuts

Macadamia nuts are much loved by many (human) Australians, and while we still don’t know the actual mechanism for their toxicity, these delicious nuts have a toxic effect on dogs. In fact, as little as 50gm of nuts will cause serious symptoms in a 20kg dog. Individual animals respond differently and often the seriousness of the symptoms is not proportional to the amount of nuts eaten.

Fortunately, the toxicity caused by macadamia nuts is not normally fatal, but supportive veterinary treatment started early will make recovery much faster and more comfortable for your pet.

Clinical signs

Symptoms usually start to show within 12 hours after ingestion of the nuts and the most obvious signs are weakness in the back legs with staggering progressing to inability to walk (sometimes all four limbs are affected). The dog has tremors, and will appear depressed and sometimes in pain, develop a fever, and vomiting may occur.


If you know your dog has had access to, or been fed macadamia nuts, ring us immediately. There is no specific antidote and inducing vomiting as soon as possible will help clear the stomach of the nuts. Other supportive treatment will depend on the seriousness of the symptoms but can include I/V fluids and pain relief.

In most cases, the dog will return to normal in about 48 hours.

One thing to note: often these nuts are chocolate coated and this can result in a more dangerous, concurrent toxicity with confusing clinical signs.


Xylitol is an artificial sweetener used widely in sugar-free gum, many sugar-free baked products and as a sugar substitute in home cooked foods such as muffins.

While it is safe in humans, in dogs xylitol is highly toxic and can lead to acute, potentially fatal liver failure. And, with the drive to lower our sugar intake, the use of artificial sweeteners is increasing significantly. Pet owners need to be alert to this particular product’s toxicity.

Xylitol affects dogs by dramatically and rapidly dropping blood sugar levels, but in severe cases, a concurrent liver toxicity also develops.

Dogs can become disoriented and develop seizures within 30 minutes of ingesting foodstuffs containing xylitol (although sometimes signs may not be apparent for several hours). Symptoms progress to vomiting, disinterest in food, lethargy and weakness and, in cases where large amounts have been ingested, jaundice develops – a sign of serious liver disease.

How much xylitol is needed for toxicity to develop? One example is sugar-free chewing gum – just 1 to 2 sticks of gum can cause hypoglycaemia (low blood sugar) in an 8kg dog (that’s a medium-sized poodle or dashchund). One case reported in vet journals documented an 18 month old staffy-cross that ate an entire batch of muffins, freshly home baked with xylitol. Intensive care maintained over 11 days was required to pull the pet through her illness.


All dogs known to have ingested foodstuffs containing xylitol require immediate veterinary attention. There is no antidote and fast and aggressive, round-the-clock treatment will be required to reverse the effects of xylitol.