I have just had one of my cows test positive for Johnes. What are the chances of other cows contracting the disease. This cow had obvious signs but none of the others show any clinical signs. My vet hinted at testing all of them, but another farmer just said to cull the cow and her offspring. The group is wintered in a loafing shed and not on pasture. Any similar circumstances or opinions appreciated. This cow was purchased with two others within the past year from a respected breeder and was in superb condition with at purchase time. I am sending her and her calf to the sale tomorrow. I hope that is the end of it. I am leaning towards testing the others to know for sure.