Circles indicate females, squares indicate males.
Solid symbols indicate dogs that have bloated.
Analysis of the pedigree When attempting to establish the mode of inheritance from a pedigree, the objective should be to come up with the simplest model that will explain the data . Therefore, we should first ask whether bloat can be explained as a single-gene dominant or recessive trait. A and D are from two normal parents. To account for this, we would have to say that that the trait is not fully penetrant, and that at least one of the parents is heterozygous. We also have to suppose that every non-bloating individual that has an affected son or daughter is a carrier.