Drowning of many animals is implied, but not shown. She has a small dog that survives the whole film, though. Dead cow and coyote (? intestines visible and part of jaw missing) shown. At one point some ancient creatures eat one of their own.
There are many tent caterpillars and a spider eating one. Many insects can be heard through most of the film (crickets, trigs, etc.), as well. Though not insects or arachnids, there are piles of live crayfish and other aquatic invertebrates.
Ambiguous. the father mentions his blood is eating itself, which usually indicates some type of blood or bone cancer. it is not directly referred to as cancer.