Unpleasant feelings about death or illness, and maybe the denial of your instinctive urges. It can also mean the killing of finer feelings. Because it is about the killing of animals see Animals.
If you have difficult feelings about killing animals or eating meat, it can be about those feelings. After all we kill whatever we eat, but as we are all from the same family we are only giving to ourselves – though the way we did it might be questionable.
Useful Questions and Hints:
What feelings do I have that underlie the images of this dream?
Am I killing something in my nature or in others? If so what is it?