I heard that in some parts of Canada, they were considering a change to their K9 procedures - instead of training them to bite, they would train them to head-butt the suspect with their muzzles. Dogs would wear a special muzzle with metal reinforced tip to protect them from injury. They thought it would be more "humane" than biting.
Well, I didn't think it would be effective - until this past weekend.
I was bending down and petting Snowy and Sasha was in front of me facing away. My daughter threw a Frisbee for Sasha to catch it. When Sasha turned around quickly, her face collided with mine.
The impact sent me flying and I ended up on my butt, dazed (I swore I saw bright orange stars). The pain was so excruciating that I had to go lie down and applied some ice. It's been several days but my face above the left eye is still quite painful to touch.
Sasha is only 58 lb (probably small for GSD standards) and she wasn't even running. If a fully trained K-9 (probably 100+ lbs) head-butt me full-force with a metal-reinforced muzzle, my retina probably would be detached from my scull. (and no doubt suffered a facial fracture)
I can't tell you if it's more "humane" - but I can certainly vouch for it's effectiveness! (I was quite "incapacitated")