Yes, we do. Idefinite number of generations. For two reasons:
1. There will always be wolf genes if CSVs are crossed only with CSVs. Genes do not evaporate with time... it is not alcohol
Their statistical percentage may vary in particular dogs depending on mathematical calucations but that doesn't mean anything. There is more to genetics than figures... a higher wolf blood percentage CSV may be very much like an ordinary dog, and a low wolf blood percentage - more independent, shier, etc. depending WHICH genes were activated in a specific match, i.e. gene combination.
But you need to remember that in the Pohranicny Straze Military Kennel methodical work was carried out towards selection of dogs that would be as doggish, trainable and work-loving as GSDs, and as healthy and strong as wolves. Although nobody cared for their appearanace, there were no random matchings! The first hybrids were trained for work and later tested. Those that did not pass the working tests were eliminated from breeding. The animals of the strongest 'wolfish' nature (most independent and shy) were simply NOT used for further breeding, because they were useless for service, however some of their genes remained in the population and their remote "echos" now contribute to the differences among particular CSVs
That's why people who know the breed put so great emphasis on the need to train CSVs and give them opportunity to work - this is the most
basic selected element of their nature and at the same time the most valuable trait of their character. It's just a great pity that some people do not understand this and treat them as show dogs only. I agree with Hanka that it's a geat waste of their potential.
2. There are plenty of wolf genes in every dog of any breed. If this was not the case wolves and dogs could not be mixed with each other. If wolves' genes were to be eliminated from dogs, all dogs would have to be exterminated
