Australian Shepherd Health & Genetics Institute

Australian Shepherd Health & Genetics Institute

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Pedigree Analysis


With all the DNA tests we have now, why should anyone analyze pedigrees?

There are over two dozen health issues, dental faults, and disqualifying colors that need to be given due attention by breeders. The great majority of these do not have DNA tests.    In addition, not every dog will have had every DNA test.  And if a recent ancestor lived before DNA tests started becoming available (aprox. 2005 for the earliest)  it won’t have been tested.

Pedigree analysis can take a lot of time and effort.  What’s the point?
If a breeder does not study pedigrees—with reference to both desirable and unwanted traits—all he is doing is producing litters and trusting to luck for good results.   This is not an effective way to breed healthy, high-quality dogs on a consistent basis.

How far back should you look in a pedigree to determine whether you might be doubling up on a problem?
When looking for specific health traits, five generations is probably sufficient.  Look for affected dogs and the parents or grandparents of affected dogs.  If there is nothing in five generations, odds are the risk of that particular problem is negligible.  Also run a coefficient of inbreeding (COI) over 10 generations to determine how closely related the two sides of the pedigree are.  High COIs mean a greater probability of doubling up on genes, the bad as well as the good.

What is the value of vertical pedigrees? 

Vertical pedigrees include the siblings of dogs that appear on a standard (horizontal) pedigree.  They allow the user to review breadth of pedigree as well as depth, the only way to deal effectively with traits with unknown or complex inheritance.  Lacking a DNA test, it can also be useful for single-gene traits particularly when you are unable to determine status on all progenitors in recent generations.

Vertical pedigrees are also handy for the traits you want to get.  The more collateral relatives that have that trait, the more likely it is your dog may produce it.

If I get IDASH pedigree analysis done on each of my dogs when I first get them, will I be able to eliminate health risk in my breeding program?

Until we have DNA tests for all the inherited diseases we’ll never be able to avoid health problems entirely and even then it will take generations to achieve.  However, doing pedigree analysis on your breeding stock, whether through a service like IDASH or your own research, will be much more effective than just trusting to luck or a hunch.

If I do an analysis of every litter and give what I find to everyone with a puppy, won’t that take care of it?

We know much more about a dog’s health and that of its relatives by the end of its life than we knew when it was born.  Because of this, pedigrees of breeding animals should be periodically reevaluated.  AHHGI recommends every three years while the dog is being bred or semen is stored.