No owner wants to make their best friend sick.Credit: iStock

Whether your best-friend is a recent addition obtained from a puppies-for-sale advertisement or a longstanding companion that has lived with you for some years, you will no doubt want to become a responsible dog owner that strives to offer a loving, warm - and above all else – a safe home for them. Unfortunately, our homes and gardens are full of things that can inflict serious harm on dogs, and what we sometimes inadvertently choose to feed our new puppy or loyal family pet could be right at the top of the poisonous-to-dogs danger list.


The following list of 22 toxic foods includes a few things you may already be aware of, but there are others only the most safety conscious dog owner would probably know … until now. These are the dog facts you need to know, if you really want to care properly for your family pet:



Onions and garlic in all their different forms (raw, cooked, powdered, etc.) are extremely poisonous to dogs – and even more poisonous to cats. The problem here is that almost all dogs love the taste of onion and garlic and particularly when combined with other foods, such as in garlic bread or beef burgers, and many people (including some experts in canine nutrition) believe small amounts are not harmful.

It is only when we start to appreciate what these vegetables do inside a dog’s body that we can understand why no amount of onion or garlic is really safe for canines.

They cause something termed ‘subclinical haemolysis’, which simply means they explode red blood cells. In small amounts, no visible physical change is ordinarily seen, but they will certainly be causing some internal damage (more so with onion than garlic), which could lead on to other more acute problems. In larger quantities – or where a dog has onion and garlic foods on a regular basis – severe and chronic anaemia can occur, as this destroys a significant volume of red blood cells.

Other dog symptoms include severe abdominal pain, lethargy, increased heart rate, faster breathing, vomiting, diarrhoea and yellowing of the skin and gums.

Related vegetables in the onion family that contain sulphur (the problem ingredient) are also considered poisonous to dogs – these include leeks and chives. It is worth noting that onions and/or garlic are commonly found in baby food and processed soups (which are safe for humans), but not for dogs. Many owners try feeding these alternatives to their dogs when their best friends are sick or not eating It is worth finding a variety that does not contain these ingredients by checking the ingredient list on jars and tins.

You will also find garlic tablets available at your local pet store, generally suggested as a flea and tick deterrent and as a homeopathic treatment of digestive problems. These are generally safe because the sulphur has been deliberately processed out of the tablet-form intended for dogs.


Many owners know that chocolate is bad for dog health, but some believe this is only due to the sugar content, when in fact chocolate intended for human consumption has an extremely poisonous substance called theobromine (as well as caffeine, which is also toxic for dogs). Dogs are extremely sensitive to this, as they metabolize theobromine much more slowly than humans, which means it can inflict serious and sometimes fatal damage.

A typical 20 kg (44 lb) dog will normally experience intestinal distress after eating less than 240 g (8.5 oz) of dark chocolate. Theobromine can cause serious heart and circulation problems long after a dog has consumed chocolate, because the toxin has a half-life of eighteen hours inside the body. Epileptic seizures, respiratory failure, internal bleeding and heart attacks are not unusual in the most severe cases.

Be aware that baking chocolate is the worst of all, as it has higher amounts of theobromine. Owners are partly right in thinking the sugar and fat content of chocolate is also bad for dogs, as research evidence shows that these ingredients delivered through consuming chocolate can lead to acute-onset and occasionally life-threatening pancreatitis several days later.


Guacamole is a delicious side-dish and dip, but you should never give any of it to your dog. Avocados contain a substance called persin. It's harmless for humans who aren't allergic to it, but large amounts are toxic to dogs. If you are growing avocados at home, keep your dog away from the plants. Persin is not only found in the fleshy fruits but also in the leaves, seed, and bark.


In 2007, the U.S. Food and Drug Administration (FDA) discovered that some Chinese imported pet food products had somehow become contaminated with poisonous melamine. These products were then later withdrawn from sale. That event caused the FDA  to pay close attention to all Chinese imported dog food and treats. Early in 2013 they confirmed they had received many complaints from owners and veterinarians that dogs and cats had become ill after eating jerky-style food and treats originating from China. In October 2013 the FDA confirmed 3,600 cases of illness, with 580 dogs dying.

The exact cause of this extraordinarily high number of fatalities remains elusive, despite the FDA undertaking 1200 different tests on different jerky-style products. The most up-to-date news is that they believe it could have something to do with a glycerine additive commonly used in the manufacturing process and/or an as yet unidentified contamination. They also found antibiotic contamination of some samples they tested, but the FDA feels this is unlikely to explain the widespread illness that has occurred among pet dogs.


Jerky treats withdrawn from sale.Credit: Tony Booth

It is worth noting that although several pet food manufacturers have voluntarily withdrawn some products that are under suspicion and FDA investigation, other jerky-style treats and foods are still being sold on supermarket and pet shop shelves. For the safety of all pet dogs and cats, I would stop feeding these products until such time as the FDA report that the problem has been completely resolved.


The link between the poisonous quality of grapes and raisins in dogs was first discovered in 1999. Acute renal failure (kidney failure) with restricted or halted urine production can occur after a dog eats a significant number of grapes or raisins. The outcome is potentially lethal, if the symptoms of poisoning are not dealt with immediately.

If you catch your dog eating grapes or raisins, the best thing to do is induce and encourage vomiting (which is what a vet would ordinarily do as an emergency procedure). Despite lots of research, the reason toxicity occurs in dogs and not in other species is still unknown. A medium-sized dog would ordinarily need to eat hundreds of grapes for acute renal failure to occur, however the numbers are much reduced in the case of puppies and smaller breads.

Vomiting and/or diarrhoea are early symptoms of the toxemia, with acute renal failure developing as quickly as within 48 hours of consumption. So if you have these fruits in your home, keep them out of reach of your best friend – and be aware that they are often found in many other foodstuffs, such as biscuits and cakes, which you may occasionally be feeding as treats or scraps.


Most hen eggs when cooked as part of a balanced diet are safe for dogs, providing they are not given too often. However, it is risky to feed a dog raw egg white and the egg yolk (and even more so if dogs are only fed raw egg white).

The problem is that some eggs are not from safe sources, which means they can contain harmful bacteria such as salmonella and E-coli. Dogs that already have an impaired immune system or are elderly or suffering from other infections and diseases, can succumb all-too-quickly to this source of bacteria. The other problem is a substance called avidin that is in egg white, which is a biotin inhibitor. Biotin is a B vitamin essential for cellular growth in the dog’s body. The yolk of an egg is actually very high in biotin, so to cut the potential for biotin deficiency it's important a dog is given both the white and yolk together.

Pasteurized egg is the safest to feed your dog, as the pasteurisation process kills off any salmonella and E-coli bacteria – however, most eggs bought in stores and supermarkets are not pasteurized. Testing of known sources in the USA in 2002 found only one in 30,000 eggs had the bacteria. Food analysts say the risk of eggs containing salmonella and E-coli is quite low, but the danger is obviously increased substantially in eggs from untested and unregulated sources and where the outer shells have not been uncontaminated through efficient washing.


Many of us may occasionally find ourselves sat in front of the TV munching on a snack of pistachio nuts – and how many of us have given one or two to the family dog, simply because he or she seems to enjoy them so much. Unfortunately, pistachios are extremely poisonous to dogs.

They are rich in phosphorous for one thing, which can lead to canine bladder stones, but they also contain aflatoxin (a toxic metabolite produced by certain fungi), which is even worse – this is in such low levels that it isn’t harmful to humans, but dogs are far more sensitive to it and run the risk of suffering acute and painful gastroenteritis. On the other hand, while peanuts and peanut butter in small quantities and given very occasionally are relatively safe for dogs (be aware that some dogs can develop an allergy to them just like humans) – pistachios, almonds, hickory nuts, macadamia, black walnuts and Japanese walnuts should all be considered poisonous to our best friends.


Raw fish is a very dangerous food for dogs, although you may find websites and magazines that say otherwise. Unfortunately, as I know only too well through living by the sea and taking my own dogs for regular runs along the beach, the worse condition the fish is in (even when it is dead and rotting) the more attractive it seems it is to dogs. Unless you are extremely vigilant, dogs will consume these carcasses in the blink of an eye.

Salmon, trout, shad, or sturgeon can contain a parasite that causes "fish disease" or "salmon poisoning disease." The disease is often fatal within two weeks, if it is not treated straight away. The first signs of illness are vomiting, fever, and enlarged lymph nodes. The cooking process kills off these parasites, making it safe for dogs to consume caught fresh fish. Raw fish can also produce thiamine deficiency, which can lead to loss of appetite, seizures, and death. Carp, smelt, herring, and catfish contain an enzyme that binds thiamine, or Vitamin B1, and sends it out of balance in the canine body, making these fish additionally risky if dogs eat them raw.


Rhubarb, tomatoes and raw potatoes all contain oxalates, which trigger abnormalities within the nervous system, kidneys and digestive tract causing tremors, seizures and heart arrhythmias. Cooked potatoes are good for dogs in moderation, but be aware that any green potatoes are best discarded.

Tubers develop a green blemish on and just under the skin, when exposure to sunlight has occurred during the growth period or after harvesting. This indicates poisonous Solanum alkaloids are in the crop. The good news is that solanine is poorly absorbed and is mostly hydrolyzed into less toxic solanidinel, so the metabolites are usually quickly eliminated. It is probably a small risk to medium-sized and larger dogs, but pups and small breeds or those dogs with existing health conditions are more likely to become unwell from eating raw or cooked green potatoes.

10. DRY DOG FOODS (when they form the only staple part of a dog’s diet)

Dry dog food (sometimes called kibble) was undoubtedly designed for human convenience, and not for the benefit of dogs as a priority. Close examination and analysis shows many varieties of this product has a third less of the essential nutrients a dog needs when compared to good quality tinned food. But the worst thing about dry food is the long-term damage it can inflict on your best friend.

Research suggests a link exists between feeding dry food throughout a dog's life - and the onset of kidney failure. Dogs fed on dry food for years are often mildly dehydrated throughout their life, and this causes damage to the kidneys, resulting in sometimes early onset of the disease. Kidney failure is incurable. Don't take the chance - feed good quality tinned food (which is about 80% water and is the easiest way of constantly rehydrating your dog) or even better, research dog nutrition and create your own homemade diet best suited to the breed of dog.


Broccoli has a toxic ingredient called isothiocynate, which is only found in the head of the vegetable and not in the stalks. Isothiocynate is a powerful gastrointestinal irritant that is extremely painful. In small amounts, broccoli has many benefits when it forms part of your dog’s varied diet, but too much at once will almost certainly give it an upset stomach and anything more than 10 per cent of the daily food intake will cause particularly harmful symptoms.


As we approach the festive season, a warning goes out to anyone that might think it apt to give a dog a sip or two of beer or in fact anything containing alcohol. Alcohol is extremely dangerous for dogs.

Something that many forget is that a dog’s body is so much smaller than a human body, which means that even a tiny amount of alcohol is like a human drinking from a bucket. Perhaps the most important thing a parent can do for their family this Christmas is let any teenagers know just how dangerous it is to give the family pet any alcohol – teenagers often don’t understand the hazard and may have a skewed sense of humour, thinking it comical and not tragic to give a dog a tipple. Alcoholic beverages and food products containing alcohol can cause vomiting, diarrhoea, decreased coördination, central nervous system depression, difficulty breathing, tremors, abnormal blood acidity, coma and even death.


Health problems ensue from both raw and cooked liver when dogs eat too much of it. Liver is actually very good for dogs, as it is rich in Vitamin A, which is essential for promoting normal vision. It also assists the immune system and the lungs, heart, kidneys, and other organs.

But too much Vitamin A leads to a state of toxicity known as hypervitaminosis – and this can cause deformed bones, spinal growths and severe weight loss. In rare but nonetheless recorded cases, it can cause death. Don’t feed your dog more than a single helping of raw liver a week – or more than two helpings of cooked liver in a week. It is worth remembering that if a dog is taking Vitamin A supplements or liver in other foods and treats, this adds to the weekly consumption level.


While both the flesh and the outer skin of an apple is good for dogs as part of a balanced and varied diet, the core of the fruit is toxic. Apple pips and some other fruit seeds contain cyanide, which are extremely toxic when a dog consumes too much or consumes the seed repeatedly over an extended period (the poison can build up inside the body without being discharged and almost without notice until it is too late).

Severe cyanide poisoning can lead to permanent heart, nerve and brain damage. In conclusion, while small amounts of apple or pear now and then is healthy for your dog, you should never give them the core or pips of these fruits. Additionally, you should also consider wilted cherries, grapefruit, oranges, limes, lemons, the seed and leaves and stems of plums and apricots all toxic to dogs.


We all know that too much coffee is bad for us, but did you know that caffeine is not only bad for dogs – but far more poisonous? According to the pet-poison help line, ‘While 1-2 laps of coffee, tea or soda will not contain enough caffeine to cause poisoning in most pets, ingesting moderate amounts of coffee grounds, tea bags or 1-2 diet pills containing caffeine can easily cause death in small dogs or cats.’

The lethal dose of caffeine in dogs is 150 milligrams per kilogram weight of the dog – and a regular cup of coffee has about 65 milligrams, so you can appreciate that inadvertent poisoning is a probable outcome of over-indulging your pet. One of the big problems is that many dogs love the taste of caffeine related drinks and foods – I have a rescued greyhound who will happily steal my mug of coffee given half a chance – which means we really shouldn't leave drinks, chocolate and other foods and substances unsupervised when our dogs are around.


The most stereotypical image of a happy dog is one seen chewing on a bone, but recent research tells us that bones are one of the most dangerous things you can give a dog. If you don’t believe it … ask your vet or the RSPCA for their advice … they will probably tell you the fact is that bones are a major cause of internal injury and are best avoided.

Carmela Stamper, D.V.M., a veterinarian in the Centre for Veterinary Medicine at the Food and Drug Administration, says: "Bones are unsafe no matter what their size. Giving your dog a bone may make your pet a candidate for a trip to your veterinarian's office later, possible emergency surgery, or even death." Bone shards break teeth, cause ruptures of the throat and windpipe, cause blockages in the intestine, bleeding of the rectum and peritonitis. The risk of injury is higher with cooked bones and even more so with poultry bones, because they break into sharp splinters, but even large raw marrow bones are now considered potentially dangerous.

It is a myth that bones are necessary for the nutritional value they offer dogs. In fact, the bone itself and the collagen in the bone cannot be digested at all. There are lots of synthetic and natural hide bones available at good pet stores, which owners can give their best friend as a much safer alternative chew.


I am sure you wouldn’t purposely feed any of these to your dog, but I am including them simply because of how common it is for dogs to eat things in the garden, such as grass … and they often chew them to make themselves vomit when their stomachs are feeling a little queasy. A well-kept lawn is particularly of concern, since it will probably be fed with chemicals, feeds and pesticides that are almost certainly harmful to your dog. Unfortunately, many gardens are full of toxic plants - and even those identified as non-poisonous plants may now be poisonous because of spraying with toxic substances.

This is not an exhaustive list and there are so many that I am only listing here those plants that begin with the letter “A” to give you an idea of the problem (please spend some time to research the potentially poisonous nature of all the plants, trees, bulbs and shrubs in your garden):

Adam And Eve (an Arum), African Wonder Tree (the seeds are the most toxic part with just one ounce being lethal), Agapanthus, Alocasia (Elephant’s Ear plant), Aloe (aloe vera plant), Amaryllis (large-flowered and popular lily), Ambrosia Mexicana (Feather Geranium), American Bittersweet (with yellow berries), American Holly (also known as English Holly or Winterberry), American Mandrake (also known as the Mayapple or Umbrella Leaf), American Yew, Andromeda Japonica (commonly called a Lily of the Valley bush or Pieris), Angelica Tree, the Apple Tree (all varieties have toxic stems, leaves and seeds), the Apricot (stems, leaves and seeds are toxic), Arrow Head Vine, Arum Lily (Calla Lily), Asparagus Fern, Aster, Australian Ivy Palm (sometimes called the Umbrella Tree), Australian Pine (also called the Norfolk Pine or House Pine), Autumn Crocus … and Azaleas (all varieties).


As dog owners, we want to give in to the wishes of our best friends and we will do almost anything that makes them happy. Unfortunately, while we may thoroughly enjoy an ice-cream on a hot summer’s day, it’s only a dog’s eyes that truly enjoy this human luxury. Ice-cream and milk have one thing in common … lactose … and many dogs are lactose intolerant. This substance is normally broken down by an enzyme in the small intestine, but just like some humans, there are dogs that lack this enzyme, which in turn means the lactose travels along the gut and causes gas, bloating and discomfort. If you find your dog seems to experience any of these symptoms within a couple of hours of having any milk product, then he’s probably lactose intolerant.

Even dogs that are not lactose intolerant should only have a small amount of ice-cream very occasionally as a luxury, and the safest flavour for them is vanilla, as it doesn’t generally contain additionally unsafe ingredients such as chocolate or raisins. It is also worth checking the ice-cream isn’t made up with artificial sweeteners, because these can cause extra health problems.

One of the worst artificial sweeteners for dogs is in fact a natural product called stevia from the Stevia Rebaudiana plant. Research has shown that this can cause a sudden and hazardous drop in a dog’s blood pressure and is best avoided when possible. Xylitol is another very dangerous artificial sweetener to avoid. This is sometimes found in flavoured yogurt and is potentially fatal to dogs, as it increases insulin output and causes the dog’s blood-glucose level to fall rapidly.


Fatty foods such as beef burgers, sausages, bacon, deep-fried products and the skin of poultry are all quite dangerous for dogs, particularly if they are given these kinds of scraps too often or in circumstances where the dog in question is susceptible to pancreatitis.

Small breeds and particularly the toy varieties tend to suffer from attacks of pancreatitis more than others, but that doesn’t mean larger dogs cannot get it too - they can – and when an attack occurs, it is extremely painful. Dogs suffering from severe pancreatitis need close-supervision veterinary treatment, which usually includes fluid therapy and antibiotics.


Yes, I thought that might make your eyebrows raise a little. I’m not talking here about the essential fresh water you no doubt serve your dog each day by filling its drinking bowl. Unfortunately, dogs are not aware that their drinking bowl is really the only safe place to quench their thirst, so they will invariably lap at any available water, regardless of how dangerous it might be.

Dog drinking from stagnant water.

This could include puddles in the pavement, pools of water at the side of the road, fish ponds, water that has collected in discarded paint and other solvent based product containers, stagnant water barrels that might be rich in bacteria and parasites, streams close to farmland or industrial sites (where dangerous chemicals might be used), swimming pools drenched in chlorine and … a warning to all men and those partners that probably find themselves forever saying ‘will you please put the seat and lid down’ … the toilet, which will almost certainly have had cleaning chemicals or possibly even bleach used on it in recent days.


Corn on the cob given whole or cut into blocks is a sure way to get your dog's intestine blocked. The corn itself will usually be digested, but parts of the cob can lodge in the small intestine if swallowed whole, and it can cause fatal repercussions if they are not removed surgically. Additionally, too many corn kernels can upset the digestive tract as well, so it’s advisable only to give a very small amount very occasionally.


In 2007, the FDA raised concerns about pet food manufacturers swapping from using very harmful chemical and artificial preservatives in their products to the natural antioxidant, rosemary. While the herb is safe for most dogs and humans in very small quantities, pet food manufacturers were introducing concentrated oils and extracts - and these very high levels of rosemary are potentially harmful, because the herb is known to cause seizures, alter neurological activity, interfere with powerful medications (including lithium) and bring about miscarriage in dogs that are pregnant. Nothing has changed since 2007 and today there are many more manufacturers using rosemary in their pet food products. My advice ... check the ingredients to find out whether rosemary is listed in the food you are giving to your dog and, if it is, swap to a safer product.

23. RICE

Rice has come under a great deal of criticism recently, because it has different forms and levels of arsenic, all with different degrees of toxicity. While most rice has small amounts of arsenic, which means it is relatively safe for humans to eat it occasionally, it has been found that many dog food products include this grain as a bulking and nutritional agent - and as dogs tend to eat the same product day in day out, there is concern about the amount of arsenic getting into our best friends' systems and the long-term health issues this could cause. The FDA is monitoring the long-term health concern for humans that eat rice regularly, but so far, it is not looking into the potential adverse effect in dogs. As a precaution, make sure you boil rice with at least six times the volume of water and then rinse it thoroughly before serving. It is also suggested pet owners consider varying the foods they feed their dogs each day, making certain they are not only eating products with rice in the ingredients.

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