There are shots of a chicken being sacrificed by being burnt alive, and a chicken being sacrificed by being bled (this could be the same chicken; both appear to be unsimulated). These images occur in the first 5 minutes of the film. To avoid seeing these disturbing images, start the film at 5 minutes in (timing based on the 2022 Trigon Films DVD edition). There are no other images of actual live animals being harmed in the remainder of the film.
The story is about a father hunting to try to kill his adult son. Spoilers, at the end they kill each other with magic, so technically an adult son does die.