Pituitary dwarfism is a rare recessive trait in some dog breeds, including German Shepherds. The pituitary gland is necessary for normal growth and development. In dogs with pituitary dwarfism, the gland does not function properly. Most dogs affected with this condition will not live as long as dogs without the condition.
Dobbie is a male German Shepherd that does not have pituitary dwarfism. What experiment could the breeder do that gives the highest possibility of determining Dobbieās genotype?