If they can only pass it on when they have symptoms and you can keep them from having symptoms thats fairly good. But I would only worry if you find you have a lethal mg. Most forms are not leathal and very mild. And most flocks in the us have one of these mild forms.
That is a very good point!
The best thing to do is to keep them healthy. @BCollie is working hard at that so I expect she will have good results.
