I don’t know what it is - it’s weird. She’s strong, but not that strong.
That being said, when I was a boy, I had a dachshund who was attacked by a huge shepherd/lab mix from next door (who had killed two other stray dogs and a couple of cats) He jumped the fence into our yard.
My girl curled up in a ball (phalanx style) and took one bite in the side from the enemy (a few stitches fixed her right up). I was running toward both of them when I saw my dog lash out - quick as a flash, and popped out the other dog’s eye - which she ate.
He ran away, never came back and the owner never said a word. She also saved my mother while she was gardening one day by killing a copperhead - grabbed it before my mother even saw it, shook it, and took off it’s head...which she didn’t eat.
I’ve always had dachshunds ever since...or rather they’ve had me.
Daschunds can be quite fierce though. Attitude goes a long way in the animal kingdom. Even in man’s kingdom too really.
Reminds me of this picture I saw of a house cat that chased a bear up a tree. If you believe you can, then you can!