crossing for longevity is bs more likley to produce dogs with problems inherent in either breed
atb
Have you been living under a rock? It's a well known fact that cross breeding has the opposite effect. Breed-specific problems are LESS likely to surface in cross breeds.
In a 13 year study on dogs Scott & Fuller (1965) found that F1 dogs were healthier, longer lived, grew more vigorously, that lactating bitches produced more milk..... but if you think you know better than these renowned researchers...
However Dunc, you haven't said what type of work and terrain you want it for. C