Using garlic as a natural flea and tick repellent is nothing new. It was bug in the 80's. I could easily buy supplements from foster and smith or other places. I don't know a lot about the author of this. But my caution flags are raised when u see she is an herbalist. Nothing against her or her practice. It can directly affect her business if people stay clear of garlic or other plants. I'm not saying she's wrong or misinformed. I'm only saying there's a possibility that she's biased. When I look at research I look to see who profits from it and or who funds the research. Depending on the source and money that research favors an agenda. If it comes from a neutral source I put more faith in the research.
I also considered that the author is a herbalist, but on the merits of the article I thought it was worth sharing. There are also many articles talking about the bad things that can happen when dogs are fed garlic. Herbalists do have a special connection with the natural world so maybe she is more informed that I. I disagree with her dosage regimen as I think that is too much garlic. :)