John P. Wagner first rose to prominence in the field of purebred dogs as a breeder and judge of Great Danes. He held a license to judge Danes for several years prior to obtaining a license for Boxers. The Wagners had imported several well known Danes, including a top winning harlequin, with which they took their first BIS in 1928. Due to the depression and Jack's ill health, the Dane kennel was disbanded in the early 30s. Casting about for the "perfect dog," Jack drew a picture of one which Mazie recognized as a dog she had seen not too far from their home in Milwaukee. Investigation revealed this paragon to be a BOXER, and the Wagners were shortly "in Boxers."

The first Boxer to carry the Mazelaine name was the future champion Landa, acquired as a puppy from her breeder, Dr. Birk, also of Milwaukee (Birkbaum). She was born in 1932, and was the forerunner of a long line of champion Boxers owned or bred by Mazelaine.

Mr. Wagner proceeded to do a tremendous amount of research in the early record of the Boxer breed and to import many excellent specimens from Germany. This naturally led to the production of the first book written in English on the Boxer ---the now famous textbook, The Boxer, published first in 1939. In the introduction, Frank Bigler predicted that the Wagner book would become the Bible of the American Boxer breeder, and he was not far wrong.

The Wagners owned and bred many of the top winners from the early 1930s until the late 50s. The two foundation sires, Dorian and Utz, were imported by them from vom Dom in Germany. They bred many of the top winners during the 40s, such as Overture, Serenade, Warlord and Brandy. Jack received numerous awards as Breeder of the Year, including the much coveted Gaines "Fido." Mr. Wagner is pictured above with Valentine Martin, another well-known breeder of the time.