Hi, I work on the premise of "combination", as both a breeder and stud dog owner I refrain from parking all the problems on one or the other. Many conditions present themselves in a recessive manner ie PRA so if puppies exibit this then both parents are at the least carriers. With hip and elbow dysplasia and malignant histiocytosis and mast cell being polygenic it is much harder to evaluate where the problems come from. Obviously xraying has helped us to eliminate using affected parents with dysplasia but those parents may still carry the fault and some dogs will contribute to the fault more so than the dog they are partnered with. This is where family history becomes important. Many health conditions particularly the inherited cancers may not make themselves known until the affected is very senior, perhaps with many descendants on the ground so nothing was able to be determined within two years of their birth but the knowledge gleaned by the responsible breeder is to evaluate the reason of the demise of the ancestors and calculate the risk factor doubling up on it when making later breedings. If, for example, I were to consider using a dog who has grandparents or a straight line of for example three dogs who all succumbed to the same disease process then I'd better make sure the incidence of that same condition is not prevalent in my own dogs.
I often think dog breeding is as challenging as walking through a mine field! But no, I wouldn't throw a bitch out for one disastrous litter unless I knew the exibited problems had occured before with her parents or grandparents or great-grandparents. Rose T.
