Foods your pet should not eat

There are some human foods and ingredients that cats and dogs can’t eat because they may be dangerous to our pets’ health.

Our research shows that 68% of dog owners and 47% of cat owners have fed their pets human food.¹ While some human foods are okay to share with your pet, others may cause upset tummies or gastroenteritis in cats and dogs and can increase the risk of illnesses like pancreatitis and kidney disease.

Many of the foods and ingredients that are dangerous to our pets are human favourites and the sort of thing you might have in your kitchen every day! Some of these potentially dangerous foods may be more surprising than others. Many of us know that chocolate can be toxic to dogs, but did you know that BBQ favourite, corn on the cob, is a common cause of trips to the vet?

Read on to find out which human foods are dangerous to cats and dogs.

Foods and ingredients cats and dogs shouldn’t eat

1. Chocolate
2. Cooked bones
3. Raisins and grapes
4. Corn cob
5. Stone fruit
6. Onions and garlic
7. Sweeteners (xylitol)
8. Nuts (e.g. macadamia)
9. Alcohol
10. Caffeine
11. Raw fish
12. Fatty foods and meat trimmings
13. Dough

If you think your pet has eaten something they shouldn’t have, or if they’re showing signs of illness, contact your vet immediately.

Pet safety: food and ingredients to watch out for

Chocolate

Chocolate contains a stimulant called theobromine which is toxic for dogs and cats. 100-150 mg of theobromine per kg (weight of pet) can be fatal. A 500g bar of dark chocolate contains 3000mg of theobromine, the darker the chocolate the more theobromine it contains.

Even small amounts of chocolate can make your pet ill, causing vomiting and diarrhoea in mild cases. A typical 250g bar of dark chocolate could cause a severe reaction in an average-sized Labrador.

Signs to watch out for include:

• Vomiting and diarrhoea
• Tremors
• Panting
• Fast heart rate
• Irregular heart rhythm

Cooked Bones

Home-cooked bones can be hard to digest and cause tummy upset along with potential damage to the gut wall, even perforation as a worst-case scenario. They can also be a choking hazard. Never give your pet cooked bones. It’s one of the most common – and most expensive – food-related pet insurance claims.

There are mixed views on whether raw bones are okay for pets, due to the risks involved with raw meat. If you’ve got a dog who loves to chew, look for bones that have been specially processed for pets in your local pet store.

Signs you should look out for:

• Lethargy
• Reduced or loss of appetite
• Vomiting, diarrhoea
• Straining to pass faeces

Grapes and raisins

Grapes, raisins, currants and sultanas; all the things you might find in a piece of cake or a granola bar are potentially toxic to dogs. We don’t know exactly which substance to blame, but we do know they’re best avoided as they can cause kidney damage and failure in pets.

Signs of kidney failure can take longer to develop and some pets are more sensitive than others, so always consult your vet if you think your pet has consumed something they shouldn’t have.

Signs you should look for:

• Vomiting
• Loss of appetite
• Diarrhoea
• Lethargy
• Abdominal pain
• Excessive thirst and/or urination

Corn Cob

It’s a BBQ favourite for humans, but corn cob isn’t a good option for pets that like to chew. While corn on its own is okay in small amounts, the cob can’t be digested and it often doesn’t pass naturally through the digestive system. This can cause a painful gastrointestinal blockage and could lead to vital but significant costs surgery or treatment.

Signs you should look out for:

• Vomiting
• Signs of pain and discomfort
• Weakness and lethargy
• Inability to defecate
• Reduced or loss of appetite

Stone Fruit

The bigger the stone, the bigger the problem. If swallowed, stone fruit (think: peaches and plums), can get stuck in your pet’s oesophagus or gut. It might sound unlikely, but gastrointestinal obstruction caused by stone fruit is one of the more common food-related pet insurance claims.

Though it’s technically not a stone fruit, avocadoes are another fruit to look out for thanks to their large stone, high-fat flesh and a substance called persin that’s potentially toxic for dogs.

Signs a stone is stuck in your pet’s oesophagus:

• Gagging
• Drooling
• Regurgitation
• Reduced appetite
• Distress

Signs of gastrointestinal obstruction (these symptoms may take 24-48 hours to appear):

• Vomiting
• Reduced or absent of appetite
• Lethargy
• Abdominal pain

Onions and Garlic

Onions, garlic, leek and chives contain a toxin that can damage the red blood cells of a cat or dog. Surprisingly, small amounts can affect your dog, even a leftover slice of pizza can make them very unwell.

These are the signs of toxicity:

• Vomiting
• Increased heart rate
• Panting
• Pale gums
• Lethargy
• Sometimes blood in the urine

Sweeteners

Xylitol is a sweetener that’s commonly added to confectionary, peanut butter, sugar-free chewing gum, ‘low-sugar’ mints, toothpaste and oral hygiene products. It’s a safe, low-sugar alternative in human foods. However, in dogs, xylitol can cause low blood sugar, resulting in liver damage and liver failure.

About three pieces of chewing gum can contain enough xylitol to cause liver damage in a 10kg dog.

Symptoms to watch out for:

• Vomiting
• Weakness or loss of balance
• Lethargy
• Tremors and seizures

Nuts

Macadamia nuts and mouldy walnuts are both highly toxic for our furry friends. Just a couple of grams of these nuts can make your pet unwell. Almonds and pistachios may also result in sore tummies. Unfortunately, these ingredients are very common in sugary snack bars which are very enticing, but certainly not healthy for our furry friends!

Signs you should look out for (generally, these signs will appear within 12 hours):

• Vomiting
• Stumbling, problems standing and using their hind legs
• Tremors

Alcohol

Any alcohol is over the limit for your pet. It’s not just drinks – alcohol can sneak its way into cakes, chocolates or even raw bread dough made with yeast, as well as hand sanitisers and mouthwashes. Alcohol irritates the gastrointestinal tract of our furry friends and can cause seizures and respiratory failure. Prompt treatment can significantly reduce the risk of a serious illness.

Here are some of the symptoms to watch out for:

• Disorientation
• Vomiting
• Lethargy
• Hypothermia
• Increased heart rate
• Tremors, seizures, coma

Caffeine

Caffeine is not just found in coffee, tea and energy drinks, but also many over-the-counter medications. Our pets are far more sensitive to the effects of caffeine than we are and the smaller your pet, the more sensitive they’ll be to its effects.

The effects will usually be seen quickly, within 30 minutes, and could last up to 12 hours:

• Vomiting and diarrhoea
• Increased urination
• Pacing, restlessness or being hyper-active
• Increased heart rate and blood pressure
• Tremors and seizures

Fish

Fatty fish naturally contains essential omega-3 fatty acids, which are good for cats’ joint and heart health and can help kittens' brain development. Fish can also provide a rich supply of protein, calcium, phosphorus, and vitamin D – all of which should be part of your cat’s diet.

However, you may be surprised to learn that fish is a common food allergy in cats. Studies show that it is the second most common food allergy in cats, after beef. It’s also important to note that some species of fish (like tuna, swordfish and king mackerel) can contain higher levels of mercury, which can cause health issues in cats. So, while many cats can eat some fish – it’s good to be aware that it might not be suitable for your cat.

Raw fish carries its own hazards. Uncooked fish, or fish that hasn’t been cooked properly, can carry bacteria (like strains of E. Coli and salmonella) and parasites, which could lead to food poisoning. Raw fish also contains thiaminase, an enzyme that degrades thiamine (Vitamin B1) which is important for your cat’s normal body function. Cats on a raw fish diet are more susceptible to thiamine deficiency, which can trigger severe neurological issues like convulsions and coma. Feeding your cat fish that has been cooked properly helps avoid this.

Signs your cat may be sick from eating raw fish include:

• Vomiting
• Watery diarrhoea
• Stomach cramps
• Decreased appetite

Fatty Food and Meat Trimmings

Dogs and cats need fat. It provides energy, and insulation, it will even help them absorb vitamins and of course, it tastes delicious to them. However, too much fat in their diet can exacerbate pre-existing conditions like diabetes, or even lead to pancreatitis, which is when the pancreas becomes inflamed. You should also be careful with meat trimmings if they have been marinated, as garlic is a common ingredient, which is toxic to both cats and dogs.

How much fat they can have varies considerably. Energetic working dogs will burn much more fat than a small dog that sits on your lap all day. If you have questions about your dog’s diet and health, it’s always best to talk to your vet.

Raw dough

Raw bread dough containing yeast can be toxic to both cats and dogs. The problems can be two-fold.

Raw dough rises – and your pet’s warm stomach can have the ideal conditions for this to happen. The expanding dough can cause bloating. Watch out for this, as well as retching/trying to vomit or a distended stomach/belly.

The other, potentially more serious issue with a dog or cat eating dough is that raw, uncooked yeast ferments the carbohydrates in the dough. This produces carbon dioxide and alcohol – another ingredient on our list of dangerous foods. Watch out for signs of alcohol poisoning (weakness, stumbling, seizures), which can happen two or more hours after your pet has eaten raw dough.

What to do if you think your pet has eaten a toxic food

Get in touch with your vet team as soon as possible. If you can, let them know the weight of your pet, what they’ve eaten (and what state it was in – e.g. garlic sauce on pizza) and how much you think they have consumed. Your vet will advise you on the next steps.

Tips to help stop your pet eating foods they shouldn’t

• Always keep foods that are toxic to pets well out of reach of curious paws and noses. It pays to be extra-cautious sound busy holidays like Halloween, Easter and Christmas when toxic treats are prolific and sneaky pets might take advantage of distracted humans.
• Be sure pets can’t get at the rubbish bag and snaffle up those leftovers! Putting leftovers in two bags, or putting them straight into an outdoor bin in that’s less accessible to your pet (and your pet’s clever nose) is also a good idea.
• Train pets to stay off the kitchen benches or keep them out of the kitchen so they don’t scavenge while your back is turned.
• Be aware of the ingredients in your meals. For example, if your pet gets their paws on a slice of your pizza, make sure they haven’t just eaten onions or garlic.

References

¹Research conducted by Pure Profile for TBWA and Southern Cross Pet Insurance 2023.

Diabetes in Cats, CareVets, accessed January 2023, https://carevets.co.nz/pet-library/diabetes-in-cats/

Pancreatitis in Dogs, VCA Animal Hospitals, Tammy Hunter, DVM; Amy Panning, DVM; and Ernest Ward, DVM, accessed January 2023, https://vcahospitals.com/know-your-pet/pancreatitis-in-dogs