Don't bother looking these dogs up. Unlike Belgium that kept the job title in the breed name, Germany rebranded the dogs to sell them.
Bouvier = Treibhund. Same word. French bouvier = German Treibhund / Viehtreiber / Kuhhund = cattle driver.
In Belgium and North France we still have:
Both recognized by FCI as Group 1 Sheep- and Cattle Dogs. They kept the old working name.
In South Germany the same type existed — Fitzinger calls it Baierischer Wolfshund, Stephanitz calls it Rauhhaariger süddeutscher Treibhund, sogen. Münchener / Riesenschnauzer. That's Bayerischer Treibhund — same job, same dog: Zusammenhalten von Schwein- und Rinderheerden [Fitzinger p.119].
Here's the exact text from Railroad rules 1912-1921:
Röll 1921, Band 9, p.328 Tierbeförderung
Enzyklopädie des Eisenbahnwesens
"Treibhunde, die zu Viehsendungen in ganzen Wagenladungen gehören, werden taxfrei befördert. Es wird aber nur ein Treibhund auf die Wagenladung angenommen."
Taxfrei = free, no freight charge. One Treibhund per cattle wagon-load.
Silence after 1921....
What makes the Lex Baiuvariorum fascinating is its focus on restoring the victim to exactly where they were before the crime. Almost every dog law in Title XX states that paying the silver coin fine was not enough. The perpetrator was legally obligated to find, train, and deliver a similar dog of equal capability (similem reddere) to the victim.