The cartoon logic of the physical being is that the body regenerates no matter what. However Coyote catches the Road Runner, once captured and contained, there would an endless source of food. Which would be a cruel torture to inflict, thus making Coyote’s torture loop all the more poetic.
[sitting bolt upright in bed at 1am] most of the ways the coyote tries to kill the roadrunner would, if successful, render it totally inedible