I don’t know how echinacea would work, or with panacur in particular. There have been a few studies that seem to indicate that echninacea works well, especially in when used with traditional antibiotics. It seems to make them work better than they do alone. Panacur is a parasitical medication right? So I’m not so sure about how it works with that. It seems to have properties that fight fungus’s as well, such as yeast.
I believe the concern with autoimmune disorders would be because it seems to increase a persons effectiveness at fighting off an infection. If you had an autoimmune disorder, your body is actually fighting itself, so the last thing you want to do is give it extra ammunition, if that makes sense.
If you live somewhere you can have a garden, Echinacea is a super easy to grow perennial that is very pretty. The leaves and flowers are safe to eat, well the root is too, but you would kill the plant harvesting it.