Well there is the dark side of mortality with friendly pets.
I've seen total breakdowns of people dealing with the death of a pet.
Even Veternarians have a higher suicide rate than dentists. Failures of any treatment ends with death and despair.
I would worry about people who have no tears or despair over their pet's passing. Its not wierd to have a greater reaction to losing a pet over losing a human. You have probably slept more often with more pets than with some people :^/