don't think you will have a problem with the limo cows but offspring could be carriers. Not a problem if your not keeping them as breeding stock and I think it's pretty cheap to have them tested if you are going to keep them.I would just breed to clean bull if it were me.That way you don't breed problems for yourself or others.I think there is alot of info at showsteers.com on th & pha including the status of many clubby bulls.
Sullivans used to bred a bunch of limmy cows to clubby bulls you might see what their doing, it's been a few years since I paid much mind to the club calf world.