So sorry to hear about your loss. You can breed two dogs together who are clear at 5 but still an offspring or two can inherit early onset MVD because the parents who are clear at 5 are only showing their phenotype for MVD. But unfortunately the offspring inherit their genes from the parent' entire genotype, not just the phenotype, and it can be very hard to know a particular dog's genotype since they only express approx. half the genes they inherited. Obviously these two inherited the genetic makeup for early onset MVD, so it had to come from somewhere. If you are able to look at all relatives, there is great likelihood you can figure out why this happened but this would be very hard to do because the information is not always available, not always reliable and especially because few people checked for MVD more than 10 years ago so you can quickly come to a dead end when trying to get information.
Although breeding two clear at 5 dogs certainly helps, due to not knowing as much about their genotype, surprises will happen--especially in the first generation or two. But if you continue to emphasize the clear at 5 ancestors, eventually more and more of the genotype will be towards later onset MVD and there will be fewer surprises. Even then a surprise will show up very occasionally. Even if you were to inbreed dogs for 2 or 3 generations, there could still be a resulting individual puppy that may not be very inbred at all genotypically due to inheriting an unusual genotype from the parents or other reasons. Just like when you breed partis to wholecolors and get a couple of generations of wholecolors and think you *lost* the parti, but then suddenly a parti shows up. You CAN improve health by breeding genotypically, it is not that we hope to improve--we CAN improve--the exact same way we are able to start a new breed of dog. If you keep stressing certain traits eventually you will have a new breed that breeds pretty true. The same goes for health problems too. There is no secret way that health trait genes work differently from type trait genes. If we can stress a Cavalier type and be successful, we can stress a health *type* and be successful too. So don't give up. If you keep breeding this way, it will get better and better and fewer of these surprises will happen. They are not really surprises to the genes, only to us, because we sometimes just don't have enough information available to us at this point in time to make the best decisions we can in breeding. But if everyone cardiologist checks their dogs and everyone breeds towards clear at 5, that information will quickly become *available* and we will be able to breed somewhat *true*, just like we know if we breed two Cavaliers together we will get Cavalier puppies. Laura Lang ========================================================= "Magic Commands": to stop receiving mail for awhile, click here and send the email: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20NOMAIL to start it up gain click here: mailto:[EMAIL PROTECTED]?body=SET%20CKCS-L%20MAIL E-mail [EMAIL PROTECTED] for assistance. Search the Archives... http://apple.ease.lsoft.com/archives/ckcs-l.html All e-mail sent through CKCS-L is Copyright 2002 by its original author.
