The focus for breeders needs to be on reducing risk and avoiding carrier-to-carrier breedings (which are the only combination that can potentially result in the fatal disease being inherited). With the vast majority of stallions and mares being untested, a breeder that tests their own mares will know either that their mare is clear of the mutation and regardless of the stallion’s status a foal would not inherit the actual disease OR that the mare is a carrier and while she herself won’t have any health risks, it will be important to know the status of potential stallion combinations for her and choose only to breed to a stallion who is himself clear of the recessive allele.