What substances are toxic to dogs?

Dogs often have their noses in all sorts of business, eating and licking various nasties they shouldn’t. Some things can be directly life-threatening, while others are only toxic in large quantities. Here we list some of the things that can cause poisoning in your dog.

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What is poisonous to dogs?

The following are toxic to dogs:

• Acorns
• Blue-green algae
• Chocolate
• Cocoa
• Dough
• Glycol
• Grapes / Raisins
• Nuts
• Onion
• Painkillers
• Poisonous plants
• Rat poison / mouse poison
• Salt
• Snail killer / slug pellets
• Toads
• Wasp sting
• Xylitol

Do you suspect that your dog has been poisoned?

To figure out whether your dog has been poisoned, find out the following:

• What your dog has ingested
• How much they have absorbed

Always consult a veterinarian if you’re unsure. If you’re an Agria Pet Insurance customer, you can get veterinary advice at any time through the Agria app. 

If you have to see a vet, it’s good to bring as much information as possible about what and how much your dog has eaten.

Acorns

Acorns contain tannin, which dogs are sensitive to as it’s corrosive. If a dog ingests a high dose, it can be fatal. Cases of poisoning have, for example, been seen in dogs weighing around 10 kilos that have ingested between five and ten acorns.

Symptoms

Fatigue, decreased or no appetite, fever, constipation, diarrhoea (sometimes tar-like). This can lead to kidney damage, liver damage and more. Can also lead to death.

Blue-green algae

Dogs that bathe or drink water from lakes or streams during algal blooms can suffer from poisoning. Blue-green algae contain algal toxins (cyanobacteria) that are toxic to your dog. Whether or not your dog becomes poisoned depends on the levels of algae toxins in the water, how long your dog bathes, and whether your dog drank the water.

What to do if your dog is exposed to blue-green algae

If you suspect that your dog is poisoned, rinse and shampoo them. Make sure your dog doesn't lick their fur.

Symptoms

Diarrhoea, vomiting, fatigue, itching, irritation, convulsions.

It’s best to get any exposure dealt with straight away, as in extreme cases it can lead to paralysis, liver damage, kidney damage, nerve damage, lung damage, internal bleeding etc. Can also lead to death.

Chocolate / cocoa

Chocolate contains theobromine and caffeine which are toxic to dogs. How much chocolate a dog can handle is individual and size dependent.

Similarly, cocoa also contains theobromine, and how much they can handle is individual and size dependent.

How much chocolate is dangerous?

The Poisons Information Center has produced examples of how much chocolate a dog can eat without being poisoned:

• A dog of 10 kilos can eat 12-40 grams of dark chocolate without getting such serious symptoms that you need to visit a vet or animal hospital.
• If the dog has eaten light chocolate instead, they can eat about 100 grams.
• Pralines, chocolate pieces with filling and so on contain less chocolate. A dog can then eat approximately twice the amount without serious symptoms arising.

Remember that the amount of chocolate will vary depending on the size of the dog.

Symptoms

Vomiting, abdominal pain, increased thirst, incontinence, tremors, increased salivation, palpitation etc. Can also lead to death.

Dough

Fermented doughs are not good for dogs to eat. The dough ferments in the dog's stomach and alcohol is formed. The condition is rarely life-threatening, but can cause great discomfort for your dog. As such, be careful to put the dough out of your dog’s reach. If they can’t smell it, even better.

What to do if your dog eats dough

Keep your dog under supervision so that your dog does not injure themselves. A drunken dog can easily get hurt on stairs or by table edges, for instance. Some dogs can also become aggressive when they get drunk as it’s an unpleasant situation for them.

Symptoms

Unsteadiness, wobble and so on. Increased desire for a kebab.

Grapes / raisins / currants / sultanas

Can dogs eat grapes or raisins? The answer is a big NO. Ingestion of grapes or raisins can cause acute kidney failure in dogs. It doesn't matter if the grapes are seeded or seedless, white, green or red.

The exact mechanism behind the toxic effect is not known, nor why some individuals are sensitive to grapes and raisins while others are not. No connection between the amount ingested and poisoning in dogs has been established. But it’s best not to take the risk.

Symptoms of grape poisoning

Dominant symptoms are vomiting that occurs 2 to 48 hours after ingestion, sometimes combined with rapid-onset diarrhoea. Abdominal pain, ataxia (shaking) and weakness may appear within 24 hours, but in most cases it takes up to 5 days for these symptoms to appear.

A dog with acute kidney failure caused by grapes/raisins requires early treatment with induction of vomiting, repeated administration of medicated charcoal, fluid therapy and intensive monitoring often extending over several weeks. Despite treatment, mortality is high.   

If poisoning is suspected, regardless of the substance, a veterinarian must be contacted immediately.

Glycol

Glycol is highly toxic to dogs, even in small amounts. Coolant and washer fluid are examples of fluids that contain glycol. Glycol is very sweet, so dogs usually find it good to lick. If a dog has ingested glycol, crystals form in the kidneys.

What to do if your dog ingests glycol

See a veterinarian if you suspect glycol poisoning.

Symptoms

Increased thirst, increased urination, shakiness, reduced kidney function.

Mushrooms

Poisonous mushrooms are dangerous for dogs. Some types of fungus are directly fatal and others can make the dog very sick. If you suspect that your dog has eaten poisonous mushrooms, it is important to contact a veterinarian as soon as possible.

Symptoms

Vomiting, diarrhoea, tremors and more.

Nuts

Some nuts are ok for dogs to eat, and some aren’t. But it’s important to know that macadamia nuts are considered extra toxic for dogs. Also keep in mind that salted nuts can lead to salt poisoning in your dog.

Symptoms of macadamia nut poisoning

Decreased appetite, vomiting, bloody stools, impaired liver function, diarrhoea, stomach problems, unsteadiness, lethargy, paralysis etc. Can lead to death.

Onions

Onions contain allicin, which is toxic to dogs. Allicin is found in both raw and cooked onions and can cause anaemia in your dog.

It’s difficult to know how much onion can lead to poisoning. As such, do not give your dog any kind of onions. This includes onion which may be included in ready-made food ingredients, such as sausages or burgers. Important: If you give your dog food scraps, bear in mind that human food often contains relatively large amounts of onion. Always be sure to check the ingredients before giving it to your dog.

Symptoms

Diarrhoea, vomiting, convulsions, reduced appetite, breathing problems, pale mucous membranes, abdominal pain etc. Can also lead to death.

Rat poison / mouse poison

Rat poison contains substances that impair the blood's ability to coagulate. If your dog has ingested rat poison, it can lead to internal bleeding. This condition can be life-threatening.

The new rat poison was approved a few years ago and contains the substance alphachloralose, which can cause convulsions and unconsciousness in dogs. What makes products containing alphachloralose dangerous is that there’s no antidote.

The symptoms come on quickly and a poisoned dog can become drowsy, have convulsions and have a reduced ability to react. In the worst case, they become unconscious.

Be vigilant about your dog when you walk in places where it’s possible that rat poison is laid out. The biggest risk is that curious dogs ingest the poison directly, but they can also be affected if they eat mice or rats that have in turn ingested the poison.

Symptoms

Bleeding from the nose, oral cavity and throat. Bruises, internal bleeding, blood in faeces etc. Can lead to death.

What to do 

Rat poison can be dangerous depending on the content, so find out what kind your dog has eaten. Go to the vet and, if you can, take the rat poison packet with you.

Salt

If your dog ingests too much salt, they can suffer from salt poisoning. Your dog may have drunk salt water or eaten salty food which can put your dog in that condition. It happens that some give salt as an emetic to their dog, which can therefore be directly fatal, especially for small dogs.

Symptoms

Diarrhoea, vomiting, stiffness, stiffness, cramps.

Snail killers / slug pellets

The use of snail killers and slug pellets is fairly common. However, the pesticides are dangerous for our dogs.

Please note that eating or licking slugs or snails, or their trails, can be dangerous for dogs. This is because they can carry lungworms. Adult lungworms live in the heart and the major blood vessels supplying the lungs of dogs and cats, they can cause potentially serious problems.

Symptoms

Increased salivation, cramps, fever, stiffness in the body, small pupils.

Toads

Toads have glands under their skin that secrete a poison that dogs are sensitive to. Your dog can become poisoned by chewing or licking a toad. This type of poisoning is usually not dangerous, but still quite unpleasant for your dog.

What to do 

Inspect your dog, especially in the oral cavity. Most of the time, you only need to keep your dog under supervision. If the dog is severely affected, you should contact your vet.

Symptoms of toad poisoning

Increased salivation, reduced pupils.

Painkillers

Pain tablets intended for humans should never be given to dogs except on the direct recommendation of a veterinarian, eg Alvedon (paracetamol) and Bamyl (acetylsalicylic acid). The dosage differs between humans and dogs and therefore needs to be determined by a veterinarian. Overdose of painkillers can lead to poisoning in dogs.

Symptoms

In case of an overdose of paracetamol: liver damage, impaired oxygen transport in the blood etc. Acetylsalicylic acid: can cause vomiting and diarrhea.

Plants

There are a huge range of plant types, and it can be difficult to know which ones are dangerous for your dog and which aren’t.

Read more about plants that are poisonous to dogs

Wasp sting

A wasp sting or other insect bite or sting is usually not dangerous for a dog. But dogs, just like people, can be hypersensitive to wasp stings and therefore have an allergic reaction. A dog, without being hypersensitive, can also suffer an allergic reaction if it’s stung several times. Wasp stings more often cause allergic reactions as they are more ‘aggressive’ than normal wasps.

What to do if your dog’s stung by a wasp

Keep your dog under supervision. If you notice any signs of an allergic reaction, contact a veterinarian for advice. In case of major problems, take them to the vet straight away.

Symptoms

Local swelling, soreness, vomiting, breathing problems.

Xylitol

Xylitol is dangerous for dogs as it lowers blood sugar levels and can poison your dog. Toothpaste, chewing gum, sweets and sugar-free desserts are examples of products that contain xylitol. How much xylitol a dog can handle is individual and size-dependent. Therefore, never give your dog anything containing xylitol.

Risk of hypoglycemia is seen if the dose of xylitol exceeds 0.1 g/kg body weight. This corresponds to 2-3 xylitol chewing gums for a dog with a body weight of 10 kg. A large intake is defined as more than 0.5 g/kg body weight.

Symptoms

Vomiting, shaking, lethargy, low blood sugar, seizures, unconsciousness. Can lead to death.