Garlic for Dogs: Home Remedies and Safety Issues

I have given each of my two dogs (retriever family, 2 and 5 yo) a clove of freshly pressed garlic every day in their dinner. They are never sick. They do Not have fleas and I DO NOT USE commercial flea/tick products which are carcinogenic and neurotoxins, and the dogs are doing great. I have not had their red blood count tested and perhaps I should. Another ? for the holistic vet I guess.

I have fed my Dingo cross bred 1 clove of garlic thinly sliced in his nightly bowl of dry food for 3 weeks so far to cure flea infestation. I have tried both top brand remedies available in Australia, (Frontline & Advantage) to no avail.The dog laps it up and the fleas have gone. No side effect so far. He does not smell like an Italian restaurant, however his coat is also very shiny. Is this too much as I have heard that Garlic is both good & bad. Most reports of bad seem to come from Vets who would lose money by not selling/promoting their sponsored product.