ALL goats & I mean all goats, should have an annual blood test done by the Vet. Most people do it around endMarch/beginning of April so it is convenient for showing.
This is a terrible disease which, if a goat is carrying it, does not show up until the animal is around 4-6 years old in average cases... occasionally it can be earlier. By then, as the disease is maternally passed as well as sexually transmitted, plus there are other methods like saliva tranmission, it is not difficult to see how dramatically this disease can spread if left unchecked.
For the relatively small amount of cost to get the blood test done.... the annual test forms can be downloaded from British Goat Society website.... the peace of mind knowing your goats cannot be responsible for the death of somebody else's beloved animals, is enormous.