You are correct. It doesn't matter if Sallie Q American values the welfare of her cat over the life of a starving child in Sub Saharan Africa or elsewhere. But Sallie should just bear that in mind when her son little Johnny is diagnosed with leukemia. Maybe that's what it would take before she'll realize the selfishness in her way of thinking.
House pets can be special things in people's lives. I get that. But to even suggest that a dog or cat is more valuable to the world than a human being speaks volumes about you. Particularly if you are not a vegan.
Simply from your use of the terms "selfishness" and "valuable to the world", we see that the conflict here is not in my failing to rank species, but in my assertion that valuing loved ones above strangers can be ethically sound, even when multiple species are involved. It appears that you tend towards collectivism and have little tolerance for those who do not.