I am worried about the fate of an injured horse. He's not my horse. I've never even met the beast, and yet I pore over news reports of his health. Maybe I am so fascinated because I saw Barbaro misstep in the Preakness, and so am "involved" in his story. But I got equally involved in the story of the dog that got drop-kicked by a local jogger, and I was nowhere near that event.
Humans respond to stories about animals. We as Americans raise serious money to protect baby seals. My guess is we raise more money for seals than we do for battered women's shelters. Organizations like PETA fight for the "rights" of animals, but ignore what's happening in Darfur.
Kick your dog, and your neighbor will call the SPCA. Smack your spouse, and chances are they will ignore it completely, not wanting to interfere.
Is this biologically hard-wired? Some mis-directed wiring that causes us to protect our animal food source, but views other people as competition? Is it cultural -- the protecting of the weak, the innocent, a higher priority than protecting those that can fend for themselves?
I see it as a hopeful sign that we can care so much for the plight of an animal. It doesn't seem such a huge leap from there to caring for a person.