Unsure if real animals were harmed, there is a very clear scene where the main character prepares a dead rabbit which is plainly on camera and he's explaining what he's doing while doing it.
There's a scene with a lot of dead fish about 20 min in, and a fairly graphic scene where the main character prepares a dead rabbit for eating at 28 minutes
multiple rabbits die, and one is shown graphically being torn apart by the main character. there is also a dead, bloody wolf head later on in the movie.