September 1935: German cavalry firing from the standing saddle position during manoeuvres on the Karshorter Racecourse, Berlin. Based on Wehrmacht eagle on uniform, it’s clearly Wehrmacht cavalry. The helmet looks like an m17 or it could be a m16.
They trained the horses that they used in battles just like Pavlov trained his dogs: making them used to loud bangs and the sight of rifles and such, by repeating these things over and over, so they wouldn’t panic when confronted with them on the battlefield. The term for this training is “Bomb-proofing”. In Pavlov’s experiment, you take an Conditioned Stimuli (CS) and associate it with an instinctual Unconditioned Stimuli (US), which causes the Unconditioned Reaction (UR) to occur when the dog is presented with the CS. In this case, the CS (a gunshot) is actually also an instinctual US, and that’s panic. You have to associate the CS with a calm environment (our US) so that the UR to a gunshot will be calm instead of panic.