What historical event in 1919 led to the official recognition of the Large Munsterlander as a separate breed?

Answer

The GLP club standardized standards to only recognize liver and white dogs

When the German Longhaired Pointer club formalized its standards in 1919, they chose to only recognize liver and white dogs, causing the black-and-white variations (LMs) to be separated and officially recognized as their own breed.

What historical event in 1919 led to the official recognition of the Large Munsterlander as a separate breed?
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