Things are never so simple when we delve:
To refrain from eating meat because of refusing to contribute to any creature's death is an error. Far too much of the earths surface has been cleared of forests to provide land for agriculture. In turn a great deal of prime agriculture land is paved and built over for urban sprawl.
The habitant of the animals is being destroyed and they are left a slow death from starvation, or else they loose cover that protects them from predators.
I recall years ago reading a study on the number of creatures destroyed by ploughing 1 acre of land. The loss of ground dwelling creatures such as rabbits, birds, fieldmice, groundhogs, moles etc. was surprisingly high. The simple fact is that we must eat to live and one way or another we are in competition with other animals.
If our un-named guest really wants to make a difference may I suggest a hunger strike. Now that would save some creatures and also remove a pimple from the Earth's arse!