I don't know if you have a similar agency in Canada, but here in the States if I came across an unscrupulous individual that was (knowingly) selling infected birds, I would report them to the local state/county extension office. We live in the country and there are poultry/egg farms in the area, in addition to the lot of us that maintain smaller homesteading/backyard flocks. A disease such as MG, because of its modes of transmission, could wreak havoc on these poultry and egg farms. I would think (hope) biosecurity measures are strictly implemented at these farms to prevent such a catastrophe, but for those who don't know any better, an outbreak could be devastating both emotionally and financially. Shame on these ppl for jeopardizing other's birds just to make a buck. I do hope you are able to get your hens as healthy as they can be!