What goes around comes around....or does it?

I used to believe in the fact that all the 'Karma' before it leaves this world, goes back and bites the ass of those who have done wrong in their life. It was logical, the world is round, things have to come back like a boomerang. But, I don't believe that anymore. I think God's changed his ways a little bit. You know probably trying something new. I think nowadays, this Karma thing has become like a game of 'YOUR IT'. I think when one person does something wrong, the bad karma that the person has called upon himself, gets randomly thrown into the direction of any other living being, it could be a nice little boy riding his bicycle, or it could be a little, ugly mouse nibbling on his cheese. So, now this other living being has to pay for the sins of someone else in this world, and once he pays the price the bad karma passes on. So, all the energy in the world is being conserved in this way, and through the misery of all the innocent in the world, God gets to test his hypothesis! Now, the problem here being, my sweet, little, polar bear resembling pomeranian is a victim, and she has a mammary tumor, which is a result of someone else's sin, it could be mine, or it could be your's. I can say this with complete confidence because, I know Candy for 14 years now and she has never gambled, or gone drinking frivolously, or bit someone without any valid, legal reason (she only bit me once on my nose, because I was really pissing her off with an annoying dance, but all this was a very long time ago, so let us all vow to never bring this up!). I hope God reconsiders this plan of his, and realises before it's too late that this experiment is failing miserably. So, for the sake of guilt, that it could, maybe be your sin that has caused my baby this pain, just remember her in your prayers. That is all that I ask.
Although, at this time, I can recollect this one specific line I heard in a movie, that goes something like this;
' The reason why God burdens you with sorrows is not because it is a test, but because he knows you have the strength to endure it'