Ask a Vet: Can Dogs Eat Garlic?

One of the questions we are asked most often is, "Can I give my dog garlic?'

The herbal combinations in all our products are completely natural and safe for your dog to eat. Garlic is one of the ingredients used and has a host of health benefits for both humans and animals.

However there are numerous articles pointing out that garlic, onions, leeks and other members of the Allium family are, in fact, toxic to dogs.

But how much would it take to have an adverse effect on your pet? And what about the benefits? We thought we'd get a definitive answer to these questions and more from Dr Nick Thompson, who has kindly written a guest article for us.

So, can dogs eat garlic? Is garlic toxic to dogs?

Garlic is toxic for dogs, right? Wrong.

Well, actually, everything is toxic. Paracelsus wrote, in Switzerland 500 years ago, "What is there that is not poison? All things are poison, and nothing is without poison. Solely the dose determines that a thing is not a poison,"

So what does this mean for dogs? Can they have garlic in their food or not? In short, yes, but there's more to it. Read on...

What will happen if a dog eats garlic?

57 varieties of blood disease?

High (very high!) doses of garlic are toxic to dogs, causing anaemia. (Cats are three to five times even more sensitive to garlic.) A chemical called thiosulphate is the culprit. Thiosulphate is a potent oxidant that affects canine red blood cells (whose job is to transport oxygen to the tissues), causing them to distort.

Haematologists can recognise these thiosulphate-damaged red blood cells because of their abnormal shape and blotches, or inclusions, within the cells. The so-called 'Heinz bodies' are a giveaway when seen under a microscope. The 'bodies' are named after Robert Heinz (1865–1924), a German doctor who, in 1890, described them in connection with human cases of destructive anaemia.

The good news is that the canine blood system is very good at removing damaged red blood cells and replacing them with brand-new ones. So if a dog has too much garlic for too long, just removing the garlic for a while will allow the body to heal completely.

How much garlic can I safely give my dog?

For everyday use, using fresh garlic, here are some approximate daily guidelines recommended by the legendary veterinary herbalist Juliette de Bairacli Levy in her book The Complete Herbal Book for the Dog (1955). She recommends::

2-5kg - up to ¼ clove
5-7kg – up to ½ clove
10-20kg – up to 1 clove
20-35kg – up to 1-2 cloves
35-45kg – up to 2-3 cloves
50kg and over – approximately three cloves

The best plan is to crush the clove before feeding (this also allows for easier peeling of the pinky papery bulb peel), then add the whole crushed clove or chop it into tiny bits.

Is garlic powder safe for dogs?

Some people like to use dried garlic powder. This is ok, but remember that one average garlic clove is only about ¼ tsp of dried powder. If you have a small dog, it's safer to just use fresh, chopped garlic for more accurate dosing of small quantities.

Benefits of garlic for dogs

Ok, so we've got this stuff that, at high doses, can cause anaemia. You may be thinking, 'why bother?'. I'll tell you why:

Studies, mainly in humans, but a significant number in animals and dogs, show garlic to be incredibly versatile and beneficial:

Raw garlic has been effectively used as a dewormer in pigs (Lans et al. 2007, Bartha et al. 2015), ruminants (Lans et al. 2007, Bullitta et al. 2018), and in cats (Ronagh et al. 2019).
A study of one hundred Swedish Marines demonstrated that ingesting raw garlic significantly reduced tick bites among soldiers.
Andrei et al. (2011) reported a 90% reduction in worm larval counts for six worm species in dogs (including various roundworms, hookworms and whipworms) following a twice-daily dose of their DIY herbal deworming mix, which included a variety of anthelmintic herbs, garlic and pumpkin seed oil.
In the doses discussed above, garlic is considered safe for use in pregnant dogs.
Garlic shows remarkable antibiotic, anti-fungal, and anthelminthic (worming) effects on dogs. I use the cut end of a garlic clove to dab onto small warts on dogs. It's often beneficial, even if your dog does smell like a French kitchen. Organic shepherds have been using garlic and apple cider vinegar for drenching sheep for worms for centuries.
Garlic boosts immunity by promoting virus-fighting T cells. Not only that, a 2011 study showed positive effects on stress and fatigue, boosting immunity.
Garlic reduces blood pressure and increases the levels of anti-clotting factors in the blood; useful in some viral diseases.
It helps reduce the effects of Alzheimer's Disease and Dementia in humans. Cognitive decline is well-recognised in dogs. Your dog's garlic consumption could be a positive life-change to ward off this problem.
Herbal medicine tells us that garlic is a mucolytic, a herb to reduce the thick viscosity of snots and mucus, in the airways, for example. It is well known to help open blood vessels, improving skin and tissue perfusion (and give away if you ate garlic the night before!).
Nutrition - garlic contains loads of sulphur - which helps the body absorb zinc, which is essential for immune health and antioxidant activity, and garlic is key to maintaining connective tissue found in skin, tendons and ligaments.

The list goes on. New superpowers of garlic are being found annually, adding to an awe-inspiring list of accomplishments.

Italians say garlic is so good for humans that it's like having ten mothers, which is saying something if you know how they worship their mothers!

Having such a bevvy of positive effects is impossible without acknowledging other areas to consider.

If your dog is on immunosuppressants, heart meds, chemo, blood thinners, blood pressure meds or insulin, discuss your addition of garlic to the diet with your vet.

Also, some breeds can be more sensitive to garlic than others. For example, dogs from countries where garlic has not been part of the culture for thousands of years, such as the Japanese breeds, Shiba Inu and the Akita, may need a much reduced daily dose.

Conclusion

When you started this short article, you may not have known whether garlic was safe for your dog. Hopefully, now you do.

We also hope you are pleasantly surprised at how much garlic can help your dog (and you!).

Maybe Italians should say, 'Garlic is so good for your dog; it's like having ten vets'.

Can dogs eat garlic for fleas?

Thank you to Dr Nick for his helpful advice - you can find more from him here and on his website.

It's reassuring to know that our blend of mint, fenugreek, neem, lemon balm and garlic are all herbs that you should be looking for when considering natural products.

These ingredient combined have proven repelling qualities and they act as a powerful natural deterrent against fleas and ticks.