Dear Merryn,

Thank you for getting in touch regarding your concerns about the inclusion of garlic in our dog food products.

There are a lot of different arguments both for and against feeding dog’s garlic is small doses. It is of course widely agreed that dogs shouldn't be fed large doses of garlic.
Our vet consultant, Dr Felicity Banks, has determined that the level of garlic used in our food is so low that a dog (big or small) would need to consume twice its own body weight of our food in one sitting before the level of garlic consumed would be of concern. In addition, over the 17 years that our product has been available, we have never had a health issue brought to us by a consumer that has turned about to be related to the garlic content of the food.

Regarding the why, Animal Nutritionist Jonathon Woodroofe has provided the following:
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Dogs have been consuming small quantities of garlic as a component of table scraps since they first started associating with humans. In fact, a committee established by the US National Research Council to examine the safety of dietary supplementation of dogs, cats and horses with garlic and other supplements noted that garlic has a long history of safe use with dogs when consumed in small amounts. Garlic has been associated with a variety of health benefits including boosting the immune system, acting as an anti-hypertensive and acting as an anti-infective.
In addition, it contains a number of nutritional valuable compounds, such B vitamins and organic trace minerals. A small, carefully controlled, amount of garlic is used in some 4Legs products. It is, however, important to recognise that many foodstuffs which are beneficial in reasonable amounts can be harmful if consumed in excessive quantities. There have, for example, been cases of toxicity in humans caused by over-consumption of carrot juice (due to vitamin A poisoning). It is true that excessive quantities of garlic consumed on a regular basis can be harmful to dogs.
Much of the present concern about garlic stems from a research trial conducted in Japan involving eight dogs 1. Four of these dogs were fed garlic at a rate equivalent to feeding a 20kg dog 100 grams of garlic a day (i.e. the equivalent of around 15 to 20 cloves of garlic per dog per day). Feeding this amount of garlic led to the appearance of damaged red blood cells but even with this very large dose none of the dogs actually developed haemolytic anemia.
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This information along with references is also available as an article on our helpdesk portal:
I've heard that garlic is harmful to dogs, so why is it in your dog food? - https://4legs.zendesk.com/entries/26512713

I hope you find this information helpful. Please let me know if you have any further questions.