Common Foods that Could Kill Your Pet

Many of us know that a huge chocolate cake is probably not going to go down well for our canine companions, but there are many other toxic foods out there that people don’t know about. In this blog post I will endeavor to cover some of the more common illnesses I have seen from eating the wrong food!

Chocolate and Coffee

 Ok so most of us know this one! But did you know why you can’t give your dog chocolate or a big slurp of your morning coffee? Chocolate and coffee contain caffeine and theobromine, which are both methylxanthines. These methylxanthines compete with the body’s natural receptors and enzymes leading to an increased heart rate, tremors, salivation, vomiting and even seizures.

If we catch the dog or cat in the act we can induce vomiting to prevent the symptoms ever developing. If your pet is already showing signs of toxicity we use products to help decrease further absorption, give intravenous fluids to help with hydration and support the body and we will give anti-seizure medication as needed to help relax them.

So how much chocolate does your dog need to eat to show symptoms? White chocolate contains very little theobromine so they need to eat A LOT for it to have an effect. Moderate symptoms of toxicity such as tremors, vomiting and diarrhea can be seen if a 10kg dog eats 100grams of milk chocolate, and severe symptoms such as seizures and heart rate issues can be seen if they eat 250grams. Dark chocolate contains much higher concentrations and 100grams is enough to see severe symptoms in a 10kg dog.


Avocado toxicity has been reported in a wide range of birds and mammals; although cats and dogs do seem to be relatively resistant to toxicity it is still best to avoid it. Pet birds and horses in particular are very susceptible. Ingredients in avocado cause necrosis of the heart muscle which ultimately leads to heart failure, although we can sometime treat cases it is often irreversible and most animals die.

Avocados may be good for our hearts but not for our feathered and furred friends!!!

Avocados may be good for our hearts but not for our feathered and furred friends!!!

Macadamia nuts

The only cases of macadamia toxicity I have seen are of dogs that live on macadamia farms! It has been reported that it only takes 24grams of macadamia nuts to cause symptoms in a 10kg dog, but generally people are only feeding one or two nuts to their beloved pets at any one time.

So first the bad news – macadamia nuts can cause tremors, ataxia (uncoordinated walking), vomiting and lethargy. But the good news is the most cases resolve within 12-24 hours even without veterinary intervention. That being said, if your dog is showing severe signs such as unrelenting vomiting or ataxia it is worth a trip to the vet just to be sure.


Vegetables from the same family as onions and garlic all contain substances known as thiosulfinates. Thiosulfinates attack red blood cells causing the haemoglobin (the oxygen carrying molecule in red blood cells) to clump together.  These clumps of haemoglobin are known as Heinz Bodies and can be seen under the microscope by your veterinarian. The unhealthy red blood cells then begin to die causing severe anaemia.

The first symptoms noticed by owners are lethargy, pale gums and heavy breathing. As little as ¼ of a cup can cause anaemia in a 10kg dog. The only treatment option for severe cases is a blood transfusion. This syndrome has been reported in birds, cats, dogs and cattle.

Signs of onion toxicity include red urine because the burst red blood cell pigment is excreted through the urinary system

Signs of onion toxicity include red urine because the burst red blood cell pigment is excreted through the urinary system



Grapes and raisins can cause renal (kidney) failure in dogs and potentially in cats and ferrets. But wait, I hear you say; my dog eats grapes all the time and is fine! Well for some reason some dogs are affected and others aren’t, we haven’t truly figured out why it happens.

But the take home message is severely affected dogs have such damaged kidneys veterinarians are unable to save them – so to be on the safe side don’t give dogs grapes!


So this is one that only affects our doggie friends. Xylitol is an artificial sweetener commonly found in chewing gum and lollies. In dogs xylitol stimulates the body to release massive amounts of insulin, the glucose regulating hormone. This surge in insulin causes a sudden drop in blood glucose levels which leaves our canine friends with absolutely no energy!

Severe symptoms include vomiting, diarrhea, tremors, ataxia and seizures. The drop in glucose can also affect blood potassium levels which in turn can have very severe side effects particularly on the heart.  Your veterinarian will treat these cases very seriously as it can be life threatening. Most dogs need to be on intravenous glucose-filled fluid with regular blood test to ensure the enzymes are returning to normal.