What if you see a malnourished kid on the roadside begging for food while you are walking your pet dog around?
I used to think about it many times but I think ever since I got to know that challenging such a situation by seeing the rich who keep pets as doing some kind of a sin could be called a socialist/communist idea and these tags are so dreadful like plague that I stopped even thinking about it. But every time you see a person walking one's well-fed pet off a poor malnourished kid, it is too painful and we realize that this world is not perfect. But again, even if we banned such practices and snatched Peter to pay Paul, most likely that system will also get corrupted with time.
I think until we are noble and kind from the heart and soul, misery will remain in this world. If this world is a stage and we are actors, script writer has written each character with some motive and purpose... But still, why should one suffer so much while other enjoys life full of pleasures?
I know that Karma provides an explanation and it is noble. Since we can't change our circumstances that we get by birth and only thing we have control of is our present, we should do good work and that will decide our future including future lives.