MVD and Pedigree Dogs Exposed

[RodRussell]

Why should the number be incorrect? ...
I am in no way trying to discredit any other study, but I live and breed in Germany and so the figures for Germany are most relevant to me, not those of the US or the UK.

I also in another post posted feedback from the stud book manager. We have in our club only one stud dog on our books who has grade 1 mvd - and he is 8 years old, and believe me noone uses him here. The majority of stud dog owners do ultrasound test - which are more precise than auskultation. We have different rules here than the mvd protocol, but that is the advantage we have rules, they are rules not a recommendation. Breeders here even do more than the rules not to have mvd. In addition to this we track every year the heart status of our dogs and this is documented in our stud book.

I have no reason to believe that there is widespread mvd amongst our population - so I will not state that every breeder in the world must follow the mvd protocol. I fully accept that in some countries this is the solution.

Dear Katherine: I am not questioning the numbers of dogs in the studies cited in the German article; I just am suggesting that, overall, there were other studies (none German that I know of) and more dogs involved in those studies which led to establishing the UK and US versions of the MVD protocol.

In the US, I suspect that there is a lower percentage of Cavalier breeding stock being examined by ultrasound to detect the onset of MVD. Auscultation is the standard here, for a couple of reasons:

First, the specialists who created the MVD protocol recommended auscultation (instead of ultrasound) because it is more accessible and costs less, and for the purposes of detecting blood backflow through the mitral valve, it is adequate.

Second, as has been determined by a Canadian study (around 1999, I think), ultrasound is much more accurate and will detect backflow earlier than will auscultation. Ultrasound is called the Gold Standard. So, if ultrasound were the standard for determining the onset of backflow, then the minimum age for the breeding stock's parents to have been cleared should be more like 4 years rather than 5 years, and perhaps even the starting age for the breeding pair should be earlier, like 2 years rather than 2.5.

What this comparison really means is that the truth is that Cavaliers develop MVD a lot earlier than when it is first detected by auscultation, but the specialists have decided that since we never will get to the point of eliminating MVD entirely (unless gene research gets us there), waiting until a stethoscope can detect the backflow is "good enough" for the purpose of reducing the incidence of early-onset MVD and trying to move that onset age back to 5 years or older.

There is an interesting hitsory to the population in Germany. Germany as you know until about 20 years ago was two countries (I think 20 is correct!). The cavalier population in East Germany was very very inbred, a geneticists nightmare! But they had never heard of heart problems and certainly did not observe them - it is quite possible that they were there and were not noticed, but msot east german breeders are convinced that they simply did not exist in their population.

This experience may parallel that of Australia and New Zealand. It may be evidence that MVD was not present at the creation of the breed, and that one or more Popular Sires introduced it -- clearly in the UK first and several decades ago -- from whence it spread, with the Iron Curtain keeping it out of Eastern Europe. My family had Cavaliers with MVD as early as the 1960s, all of which were imported from the UK.

Rod Russell
Orlando, Florida USA