As a responsible breeder you will know that some breeds, especially the numerically 'small' breeds where there are relatively few distinct breeding lines, are at considerable risk of problems arising from loss of genetic diversity in the breeding population.
This can give rise to serious problems due to persistently high levels of inbreeding which may have alarming consequences for certain breeds. It is a problem often exacerbated in pedigreed dogs and cats by the overuse of prominent sires.
One thing you can do as a breeder is to keep an eye on the prospective inbreeding that will result from a mating. To do that you need to have sufficient pedigree data available to you - i.e. details of breeding lines that go back far enough for your breeding software to be able to compute a meaningful inbreeding coefficient. It is quite ineffective to only go back say 3 generations when computing the inbreeding if it so happens that in your pedigree there are no common ancestors within 3 generations, whilst if you go back say 6 there are many. In such situations the computed inbreeding to 3 generations of 0% is a grossly misleading figure.
For the smaller breeds, what matters is that the maximum amount of genetic diversity is maintained. This means more than simply selecting for low coancestry for prospective breedings. E.g. it is possible that the genes from a particular founder in a small breed are badly represented in the current breeding population (in comparison to other founders, that is), and that selecting to increase the genetic contribution of that founder is actually more important, initially, than purely selecting for the lowest inbreeding - because it may increase the presence of that founder's genes within the current, active, breeding population.
Customers interested in these issues should refer to our advanced pedigree analysis software PedScope which can help you make exactly these kinds of breeding selection decisions.