
you may find beacuse she has a congenital heart disease which this mean that the dog devloped this while being form in the womb,or the result could have been through,the mum bumping into something,or medince,etc it could 1001 things that may have cause it,or the puppie beening drop at a young age so on,so the other sibleing,may not be affected with it,and you be worrying the owner of the dogs,it be different if it was a hereity problem,where it is carried down the genes from the pearnets,have you gone back to the breeder,i think it be best for the breeder to find out if the other have it, as they should have the address were the other puppies have gone to,it should be down to the breeder not you to do the seach.do they know of the problem with your puppy.
how is kimba,at what age was it pick up,on her first vist to the vet for a health check or other vet vist.has she gone to a spec,and had a scan /ecg.etcwhat the out come.