Onion and garlic toxicity in dogs

Onion and garlic toxicity in dogs is fairly uncommon; however, symptoms can be severe so it’s important to be aware of the risks. Most dogs recover well without any long-term problems from onion and garlic toxicity.

Contact a vet straight away if your dog has eaten onions or garlic, no matter the quantity. Your vet will determine if any further treatment is necessary, depending on how much was eaten and what size your dog is. Any age of dog can develop poisoning. The most common symptoms are due to irritation of the mouth and tummy.

Overview

What is onion and garlic toxicity in dogs?

Onions and garlic are part of the Allium family of plants, which also includes leeks, chives and spring onions. These can all cause illness in dogs when ingested.

Onions and garlic are a kitchen staple, found in many meals, baby foods, soups, seasonings, sauces, and even human supplements. They are poisonous when raw or cooked.
Powdered and dried forms tend to be more concentrated so they are more likely to cause illness.
Garlic is thought to be the most potent of the Allium family. It’s five times more toxic than onions.
Alliums contain toxins called disulphides and thiosulfanates. These toxins can damage the red blood cells in the body, leading to anaemia.
Ingestion of very small amounts might not cause any problems.
Signs of garlic toxicity usually start within 24 hours if a large amount has been eaten. Signs can sometimes be delayed for up to a week, especially when eaten in smaller amounts.
In extreme cases, onion and garlic toxicity can be fatal in dogs.

How much onion and garlic causes toxicity in dogs?

It varies between every dog and the exact amount is not known. Some studies have shown that for garlic, ingestion of over 15-30 g/kg of body weight can cause anaemia in dogs. And for onions, ingestion of over 0.5% of body weight can lead to signs of toxicity. These are estimates and smaller amounts can cause severe problems in some dogs.

Call us now if your dog has eaten onions, garlic, or anything else that may be poisonous. Our Joii vets can help you with the next steps. We are available 24 hours a day.

Symptoms

Symptoms of onion and garlic toxicity in dogs

The symptoms of onion and garlic toxicity depend on how much is eaten. A larger quantity or a more concentrated form (like powder) causes more severe symptoms.

Common signs include:

Vomiting
Diarrhoea
Drooling and irritation of the mouth
Lethargy and reduced appetite
Tummy pain

Eating larger amounts can lead to damage to the red blood cells. Symptoms include pale gums, breathing problems, and red urine. Find out more about anaemia in dogs. Red blood cell damage can lead to kidney disease.

Risk

Are some dogs more at risk of onion and garlic toxicity?

Dogs that scavenge and curious puppies are more likely to ingest onions or garlic from the floor or rubbish bin.
It’s been shown that some Japanese breeds of dogs, including Akitas and Shiba Inus, are more susceptible to garlic poisoning.

Diagnosis

How is onion and garlic toxicity diagnosed in dogs?

Diagnosis is usually based on the history and clinical signs. It’s important to let your vet know if your dog has eaten any onions or garlic and how much. Tests that may be needed include:

Blood tests: to check red blood cells and kidney functions
Urine tests

These tests are usually repeated after a few days, as the damage may not appear until up to a week later.

Vet treatment

Vet treatment for onion and garlic toxicity in dogs

If caught early, usually within 2-3 hours, your vet will most likely give your dog an injection to make them vomit. This helps to remove as much of the toxin as possible. Further treatments depend on the severity of the signs and may include:

Hospitalisation for fluids and monitoring
Anti-sickness medication
Tummy protectants
Activated charcoal to prevent absorption of the toxin in the tummy
Blood transfusion and oxygen therapy if severe anaemia is present

Home treatment

Home treatment for onion and garlic toxicity in dogs

It’s important to contact a vet if your dog has eaten any plant in the Allium family before attempting any home treatment. In mild cases, it may be possible to monitor at home.

Make sure your dog is drinking normally
Monitor their urine and stools for anything abnormal (such as a change in colour or consistency)
Feed small meals of bland food, such as eggs and rice, if they have vomiting or diarrhoea
Use a probiotic to help improve the stools

Prevention

Tips on how to prevent onion and garlic toxicity in dogs

When cooking, make sure to clean up any spills on the floor straight away
Don’t leave any leftovers on the table or kitchen counters
Make sure your rubbish bin is secure and never leave your dog home alone with access to it
Prevent access to any dangerous plants in the garden by using a fence
Avoid giving your dog any human food; stick to dog food and treats specifically made for them

When to worry