Generally that it also my own conclusion. Dogs are known for their highly acidic and I would assume highly bilelic intestines. I know bilelic may not be a word but it should be. Anyhow, they come into contact with lots of parasites eating doo and all that. Yet most of them are okay, especially the ones who eat a more natural diet.
But yet many animals do get parasites even wild animals. So I think it is a part of the picture to have bile flow, but not everything. Luckily, we are human and have many options available to us. I think that with herbs and a healthy digestion and perhaps a little fasting sometimes we can pretty much knock out anything.