i.e. you will be subjected to a given personal injury or torture method unless you are willing to perpetrate it on a given animal.

e.g.
I'd definitely put a dogs feet in boiling oil to avoid having my feet put in boiling oil, but I probably wouldn't kick one in the stomach to avoid being kicked in the stomach. So I'd pick somewhere in the middle. I reckon I'd break a dog's leg to avoid having my leg broken, but anything less horrible than that I'd do to the dog.

If you hate dogs, do it for a cat. If you hate both, please pick an appropriate animal and don't take the piss.