The dog dies: use of animal death as an emotional pull in film
A number of movies, tv shows, and other pieces of fiction use animal death for one main reason. Generally, it's to show a particular character is evil, and to pull on the viewer's heartstrings by showing the death of an innocent creature (most often, a dog).
This technique is often very effective, and many viewers feel very emotional at the death of animals on screen, to the point that sites such as 'Does the Dog Die' exist simply to warn viewers who find animal death (among other things) to be too much. But due to being effective, some find it over-used, a bit of a cliche.
So, why is it used so often? Is it just so effective that it's worth the cries of unoriginality? Is it just such a simple way to portray a character's cruelty? And why is it so effective, anyway? Why is the death of an animal more effective than that of say, a child?