I didn't read the entire article, but what I did read concerns me. Yes, there must be certain conditions for dogs to get HW. Many, many dogs do get HW and need treatment. Many dog die without treatment. I would rather use the preventative than need the Immiticide treatment.
My pup is almost a year now. He came from a high kill shelter in SC. He had demodex and microfilariae, when I got him. He was on Ivomec for months. The demodex went away. The microfilariae did not. While my pup never tested positive for adult HW, it was confirmed that he did have "new" microfilariae, which would only be from adult HW. He has been through the Immiticide treatment. Last week, he went back to the vet for his one month followup. Guess what? He STILL has microfilariae.
"Boh's" blood has been sent to VT vet school. The professor requested LOTS of blood, because there are many people who will want a sample. I am still waiting to hear back, but I can honestly way that if'/when, I get rid of these things, I will do everything in my power to make sure he never gets them again.