Every pet owner enjoys giving their beloved pet a nice treat every once in a while. It might be the leftovers of your dinner or just some other human food they really have their eye on. But owners should beware: your well-intended treat may actually harm them.

Many foods we enjoy can be dangerous to our animal friends. It’s usually best to stick to pet food and a diet recommended by your vet. Here are a few common foods that can be toxic for your pet if carelessly left around or given to them as a treat.

Chocolate, Coffee and Caffeine

These products contain methylxanthines, which when ingested by pets can cause vomiting and diarrhoea, panting, excessive thirst and urination, hyperactivity and seizures. Theobromine, a compound present in chocolate, is a cardiac stimulant which is especially dangerous for dogs.

Theobromine can increase a dog’s heart rate or cause the heart to beat irregularly. Death is a possibility, especially with exercise. The signs of sickness usually won’t be seen for several hours. The darker the chocolate, the more dangerous it is.


Avocado can cause cardiovascular damage and death in birds while horses, donkeys, goats, sheep and rabbits can suffer from swelling and oedema (build-up of fluid in cells) in the head and neck. They contain a toxic component called persin which can also damage heart, lung and other tissue in many animals including dogs and cats.


Onions contain thiosulphate which cause sickness in dogs, cats and livestock. Pets affected by onion toxicity develop a condition where their red blood cells burst while circulating the body. When first affected, it will cause vomiting, diarrhoea, loss of appetite, breathlessness and weakness.

Poisoning usually occurs a few days after eating the onion. Red pigment caused by the burst blood cells can often be seen in the affected pet’s urine. Cats are generally affected worse than other animals. Garlic and chives also contain thiosulphate but a lot more needs to be eaten to cause illness.

Grapes and Raisins

While the cause of toxicity in grapes in not understood, these fruits cause sickness in dogs, cats and other pets. Grapes can cause vomiting, lethargy, thirstiness and diarrhoea hours after consumption. The worst case scenario is kidney failure.


Almonds, pecans and walnuts all contain high amounts of oils and fats which can cause vomiting, diarrhoea and potentially pancreatitis in pets. Macadamia nuts also cause debilitating sickness in dogs, who develop a tremor of the skeletal muscles, swollen limbs and weakness or paralysis of the hindquarters.

Signs usually appear within 12 hours and can last up to two days. The similarity of symptoms causes the condition to sometimes be mistaken for tick paralysis.

Other Dangerous Foods

The above foods are the most common causes of serious illness in pets, but there are many others that can cause mild or severe sickness that should be avoided, including:

  • coconut
  • milk and dairy
  • fatty meat
  • salty foods
  • alcohol
  • xylitol (artificial sweetener)
  • yeast dough
  • human medicine

If in doubt, always consult your vet before introducing a new treat to your pet. For fast, professional veterinary treatment in Sydney, visit Northside Emergency Veterinary Services.

Call us now on (02) 9452 2933 or contact us online for more information about food safety and pets.