Approximately when did the German Shepherd Dog Club (SV) begin actively discouraging the breeding of white dogs in Germany?

Answer

By the 1930s.

The shift in breeding standard regarding white coloration began to solidify in Germany around the 1930s. During this period, the German Shepherd Dog Club (SV) started taking active measures to discourage the breeding of dogs with white coats. The justification provided by these clubs often involved assumptions that the white gene was linked to faults in either the dog's structure or its temperament, although breeders who championed the white lines often contested this, believing the motivation was rooted more in aesthetic preference solidifying into an enforced rule.

Approximately when did the German Shepherd Dog Club (SV) begin actively discouraging the breeding of white dogs in Germany?
evolutionDogwhitebreedGerman Shepherd