Care should be taken that they aren t bred to other carriers and those who buy puppies from a carrier parent should be advised to screen the pup if they want to breed it. But eliminating proven carriers as breeding stock is throwing our their many good genes while avoiding one bad one. Australian Shepherd breeders are doing this with Pelger-Huet Anomaly. PHA is lethal to offspring that inherit two copies of the gene, resulting in reduced litter size and neonatal deaths. Carriers rarely suffer any effects.
Knowledgeable breeders use a blood test to screen and carriers are bred to non-carriers.
Less specific aspects of health must also be considered. These individuals likely carry a surplus of genes which individually have only a small negative effect on health but cumulatively have produced an unthrifty individual. Bitches from families that consistently produce small litters may be suffering inbreeding depression. Animals which can only be bred or raise their puppies if they receive extraordinary human assistance are poor breeding candidates. This is not to say that people shouldn t properly house and care for their animals, but if a dog is indifferent to bitches in standing heat or a bitch needs to be physically restrained to keep her from resorting to fight or flight in an attempt to prevent mating, or won t settle without veterinary intervention, or is apt to kill or damage her puppies through intent or neglect, these are signs of inbreeding depression and that animal shouldn t be bred.