Which foods are toxic and poisonous to dogs?

Dog eating from a bowl

There are plenty of human treats that we could be tempted to spoil our furry friends with. Although their puppy dog eyes can draw you in and tug at your heartstrings, it’s important to keep well away from certain foods that could be incredibly dangerous to your dog. Some foods could result in vomiting, diarrhoea or even death.

Onions, garlic, leek, and chives are commonly used as ingredients in many dishes due to their strong aromatic properties. In dogs, these ingredients can cause anaemia from red blood cell destruction and dogs are highly susceptible to poisoning from human food containing them, even when the food is cooked thoroughly. Common signs of poisoning from these ingredients include vomiting, diarrhoea, abdominal pain, loss of appetite, and depression, but don’t wait to see! If you think your dog has eaten anything containing these, call their vet ASAP.

Ethanol is an alcohol found in a variety of products, such as alcoholic beverages, medication, perfume, mouthwash, some thermometers, and certain forms of antifreeze. It is also used as a disinfectant and in many hand sanitisers. Usually, ethanol poisoning in dogs comes about as a result of accidental ingestion of alcoholic beverages but can also be due to eating uncooked bread and pizza dough, which contain yeast that metabolizes carbohydrates to ethanol and carbon dioxide. Toxicity causes central nervous system depression, and clinical signs range from lethargy/depression and incoordination to tremors and death.

Grapes and their dried products (raisins, sultanas, and currants) can cause kidney failure in dogs. The fruits may be ingested raw or cooked as ingredients of fruit cake, mince pies, malt loaf, snack bars, scones, and other baked goods. Ingestion of any quantity of these fruits is potentially dangerous, and can result in vomiting, loss of appetite, lethargy, abdominal pain and even death is kidney failure is severe.

Chocolate contains a substance called theobromine, which dogs and some other animals struggle to metabolise. Most poisoning cases occur because of chocolate ingestion. Chocolate poisoning episodes are more common around the holidays, particularly Easter or Christmas time when there is a higher occurrence of chocolate products in the home, and most likely, in your office too. Small amounts of theobromine can cause vomiting and diarrhoea, but higher doses can cause seizures and occasionally death. A vet should be able to advise on how serious the situation is based on the size of the dog and the quantity ingested.

Xylitol (also known as E967) is a naturally occurring sweetener that is used in many food products instead of sugar, including sugar-free gum, mints, sweets, and some baked goods and peanut butter. It is also sometimes used in dental products, such as mouthwash and toothpaste. Xylitol can stimulate insulin release in dogs, leading to a dramatic crash in blood sugar levels. It can also cause liver failure in dogs and could be as fast acting as under an hour before signs appear, or it could be up to 12 hours before any signs appear. Therefore, if you suspect your dog has consumed anything with Xylitol, contact their vet immediately.

Avocados have become very popular in recent years, but these fruits contain persin, a fungicidal toxin. It could cause serious health issues if a dog eats too much, so steer clear of any at all. Persin is mostly located in the leaves and bark of the avocado plant and in the pits and skin of the fruit, but it is also found in the flesh of the avocado in a less concentrated amount. Unripened fruits also contain higher amounts of persin. It’s best to err on the side of caution and treat all parts of avocado as potentially be hazardous to dogs.

Tea and coffee (and hot chocolate) feature organic compounds that can be harmful to dogs, including caffeine, theobromine, and theophylline. These are also commonly found in a variety of foods, beverages, human medication, and other products in the home. Caffeine is found in coffee, tea, guarana, and as an additive in many soft drinks. Theobromine is found in cacao seeds and in products manufactured from these seeds, such as chocolate. Theophylline is found in tea along with caffeine. Caffeine is also used in human medication to increase mental alertness, and theophylline is widely used in anti-asthma drugs. All of these are harmful if ingested by dogs so should be kept away (and dogs certainly shouldn’t be allowed a sip of tea/coffee with their own breakfast.)

Macadamia nuts are produced by trees of the genus Macadamia and are very popular as snacks for human consumption, both as plain nuts or when used in cakes, cookies, or in nutty chocolate bars. Even ingesting a tiny amount of macadamia nut can be very harmful for dogs. If your dog eats macadamia nuts, they could become very ill, including showing muscle weakness (particularly hind limb weakness), depression, vomiting, co-ordination problems, tremors, hyperthermia, abdominal pain, lameness, and stiffness. Call a vet if you think they have eaten some so that action can be taken before signs occur. 

Give a dog a bone?

Although popular culture would lead us to believe that bones are great for dogs, you need to be really careful if a dog is given, or acquires, a bone. Take care to ensure your family and friends know that they shouldn’t be giving your dog leftovers, like their chicken drumsticks from lunch. Bones can cause constipation, obstruction of the throat/gut or even pierce the gut which can be fatal.

This list is not exhaustive. If a dog has ingested (or you suspect they have ingested) any of these call a vet immediately.

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