I have a cat, actually. And my personal experience of love is that no two are alike, and that I have for animals is very different in nature. What "category" a love falls into (romantic, platonic, familial, etc) doesn't seem to have any impact on how strong it will be, for me. My top three loves all come from different "categories."
My point is that I don't see any evidence that parental love is "superior." There are a great many parents who don't seem to love their children very much, if at all.
What courts would do proves nothing except one society's take on animals. In India, there was a time when killing a cow could be punished by having your hands cut off. In Janism, even the killing of insects is quite serious.
"Justified"? If you believe love needs to be "justified," then you don't understand the concept well enough for us to be having this conversation.