It feels like it’s a cute bonding thing to do, sharing human food with our dogs, but it’s really important to be very careful when giving our dogs human food.
One of the most common mistakes dog owners make is assuming what’s fine for us is fine for dogs. In fact, several everyday foods can be extremely dangerous to dogs, even in small amounts.
Here’s your complete guide to never feeding your dog certain human foods, including what the risks are, how much can cause harm (where known), and what to do if something goes wrong.
Which Foods to Never Feed Your Dog
It’s easy to assume that “natural” or “healthy” for humans means safe for dogs too, but that’s not always true. Many common foods can cause serious problems, even in small doses. Let’s look at the main ones to avoid and why.
Chocolate
Out of all human foods that are dangerous for dogs, it’s pretty well known that dogs shouldn’t have chocolate. Chocolate is a delicious sweet treat for us humans, but dogs should definitely stick to natural dog treats and chews instead.
Chocolate contains theobromine (and caffeine), which dogs process far more slowly than humans.
Even small pieces can cause vomiting, tremors, or an irregular heartbeat, and larger amounts may lead to seizures or death.
Signs of toxicity may start from around 20 mg theobromine per kg body weight, with serious effects at higher levels.
Dark and baking chocolate are the worst offenders. A small amount can be dangerous for a small dog.
Watch out for symptoms such as vomiting, restlessness, a racing heart, tremors, and seizures. If your dog has eaten chocolate, call your vet immediately.
Grapes, Raisins, Sultanas, Currants
This one might come as a bit of a surprise, with a lot of fruits being fine for dogs to eat in moderation, but grapes are one of the absolute worst human foods that your dogs can have.
There’s no safe amount, and some dogs react far worse than others. One dog might eat a handful with no problem, while another could get seriously ill from just one or two. It’s simply not worth the risk.
Watch out for vomiting (often within a few hours), loss of appetite, tiredness, belly pain, and little or no urination. They’re all signs that your dog’s kidneys may be struggling.
To stay safe, keep all grapes and dried vine fruits out of reach and avoid sharing anything that contains them, like fruit loaf, cereal bars, or flapjacks.
Onions, Garlic, Leeks, Chives (Allium family)
Onions, garlic, leeks, shallots and chives all belong to the Allium family. These plants all contain a substance called thiosulfates, which can damage red blood cells in dogs and can cause life-threatening anaemia.
Clinical signs have been recorded from about 15-30 g of raw onion per kg, but powders and cooked foods can be even worse (because of the higher concentration).
Watch out for weakness, pale gums, rapid breathing, and dark brown urine. If your dog has eaten an onion, seek veterinary advice straight away.
Xylitol (Sugar-free sweetener)
Xylitol is extremely dangerous in dogs. It causes a rapid insulin release, leading to hypoglycaemia (low blood sugar) and, in higher doses, liver failure.
In dogs, around 100 mg xylitol per kg may cause the first signs, and around 500 mg/kg may trigger liver injury.
Xylitol is commonly found in sugar-free chewing gum, mints, peanut butters, cakes, and some dental products.
Signs that your dog has eaten something with Xylitol include vomiting, wobbliness, collapse, seizures, and yellowing of skin/eyes (jaundice). If they have eaten something with Xylitol, seek veterinary advice straight away.
Caffeine (Coffee, Tea, Energy Drinks & More)
Caffeine gives us that morning boost, but for dogs, it’s highly toxic, and even small amounts can cause serious problems.
It belongs to the same chemical family as theobromine (the substance in chocolate), which means it affects the heart, muscles, and nervous system in a similar way.
Even a small sip of coffee or a few nibbles of used grounds can cause symptoms like restlessness, fast breathing, trembling, and an irregular heartbeat. Higher doses can lead to seizures or collapse.
Caffeine is found in coffee beans, grounds, and brewed coffee, tea bags, energy drinks, painkillers, and cold medications.
As little as 20 mg of caffeine per kg of body weight can cause early signs of toxicity, and 100 mg/kg or more can be life-threatening.
If your dog gets into anything caffeinated, don’t wait for symptoms. Call your vet right away, and they can calculate the likely dose and start treatment quickly if needed.
Alcohol
Dogs and alcohol don’t mix, ever! Even tiny amounts can make your dog seriously ill. They’re far more sensitive to ethanol than humans, so what seems like a harmless sip to us can quickly cause poisoning.
Alcohol affects a dog’s brain and liver just like it does ours, but much faster and with more severe consequences. It also causes low blood sugar, low body temperature, and dehydration, which can become life-threatening in small dogs or puppies.
Dogs are far more sensitive to ethanol than humans. A lethal dose of 100% ethanol is roughly 5.5-7.9 g/kg in dogs, but much smaller amounts can cause severe issues, especially in puppies or small breeds.
Watch out for vomiting, disorientation, wobbly movement, low body temperature, and collapse. If ingested, seek veterinary advice straight away.
Macadamia Nuts
Macadamia nuts are another mystery toxin, and we don’t fully know what makes them harmful, only that they are. They can cause weakness (especially in the back legs), tremors, vomiting, and fever within 12 hours of being eaten. Signs can last a couple of days, but are still very distressing.
Watch out for weakness, wobbly movement, vomiting, and fever. If eaten, contact your vet quickly.
Mouldy or Spoiled Foods (including mouldy nuts, bread, cheeses)
We’d turn our noses up at mouldy leftovers, but a dog definitely wouldn’t. That sour smell that makes us gag can actually attract them, especially if it’s in the bin or compost.
The problem is that mouldy or spoiled food can contain dangerous toxins, known as tremorgenic mycotoxins, which can cause tremors, seizures, and vomiting (often within minutes of eating it). These toxins are commonly found in foods such as old bread, nuts, and cheese.
There’s no safe amount, and even a small nibble can lead to serious symptoms.
Watch for drooling, restlessness, trembling, vomiting, muscle twitching, or collapse.
To be safe, keep bins tightly closed, clean up food waste promptly, and make sure compost heaps or recycling containers are secure. Dogs love a good rummage, and what smells gross to us might not to them.
Cooked Bones
It’s a common misconception that dogs should always have bones, but cooked bones are actually dangerous. Cooked bones may splinter, block the intestines or perforate the gut.
The safest options when it comes to bones are raw or air-dried bones and chews made specifically for dogs. Cooked bones are never safe, as they can splinter and cause serious injuries. Even with raw bones, always supervise your dog, and choose an appropriate size.
Watch out for gagging, drooling, vomiting, abdominal pain, and blood in stool. If your dog has swallowed a cooked bone, contact your vet immediately.
What to Do If Your Dog Eats Something Unsafe
1. Stay calm but act fast. Time is really important. The sooner you speak to a vet, the lower the chances of your dog being poorly.
2. Call your vet or Animal PoisonLine, or if it’s out of hours, your local emergency 24-hour vet is the best bet.
3. Do not induce vomiting unless your vet tells you to.
4. Keep packaging or remnants of the item so ingredients can be checked.
Final Thoughts
When in doubt, the best thing to do is assume a food is unsafe for your dog. It’s just not worth the risk, especially when there are so many delicious, natural treats that are perfect for dogs.
At Cloud K9, we believe making safe dietary decisions reinforces trust and love between you and your dog. Treats and food are an important part of our bond with our dogs, and they play a huge role in their health, well-being and overall health. We always recommend dog-safe, natural treats and chews designed especially for dogs.