We had a bit of a rough day yesterday. K's rabbit, Daisy, died. K had been begging us for a rabbit since she was 4-5 years old. We had told her that when she turned 8, she could have one (thinking by then, she'd have forgotten all about it!). The joke was on us because right before her 8th birthday she asked when we could go get a rabbit! Never underestimate the memory of a child.
I think it's a good thing for kids to have pets. Mine have learned responsibility by being the one in charge of another living creature, what happens when a boy rabbit and a girl rabbit are put together (made talking about the facts of life pretty easy!), and that life is finite. All worthy lessons.