Disintigrated, vaporized, exorcized, and demoralized!!! Send that biatch back to hell!!!
The laser is just another wavelength of light, causing a radiation burn, and while some of the animal is recieving the full potential, much of it is not, and pieces of flesh contaning live cells are both left behind, and released into the water.
IMO- The laser would have to be a larger diameter and very powerfull, encompasing the entire animal, for some length of time.
I am not saying its impossible, just VERY impractical.