The fighting den included a blood-soaked carpet to make the dogs aggressive, as well as a canine treadmill for training, and a bolt gun used to put badly wounded dogs to death, police confirmed on Monday.
The 50-year-old ringleader and owner of the house in Ettenheim near Freiburg, is on the run, and could already have left the country.
The authorities are working on the assumption that the contests drew a sizeable audience, filling the beer tents which had been set up around the dog fight cage.
Detectives will also work to track down the spectators of the fights.
That wasn’t the only discovery awaiting officers who had responded to a tip from fellow dog-owners; they also recovered 450 marijuana plants from a nearby warehouse.
Police were able to rescue 11 pit bull terriers which were taken to animal rescue centres.