I Could Never Understand...

Why do they euthanize dogs that bite people?

I mean, I have a cat that bites the shit out of anything that moves. No one would euthanize her.

Or, better, pets that you KNOW will kill you. Like aligators and reticulated pythons and A. seemani tarantulas :3. Is it because we already expect them to be pissy fuckers? No one distroys them after they bite someone. (And no one expects them to be distroyed.)

So, somehow, because a dog defies our expectations of what it should be, it gets killed?

...sorry, just had to voice this.