Meh, I'm indifferent towards animals dying. It's sad, but once you've seen a couple, you start caring less. I've seen about 6 pups die from sickness, or just being ran over by a car. Another was carried off by a Hawk...pretty sure that guy didn't make it afterward.
I've seen about 2-3 adult dogs pretty much murdered viciously by my Pit bull. Bear in mind we didn't force this dog to fight, he was just very protective. I remember being a kid, and waking up to hearing some dog screeching in horror outside my room, only to see my dog, Champ, clamping on to it's neck, aggressively swinging it back and forth, eventually seeing it's spinal column coming out of it's body. Gross.
I also remember my dog getting loose from his leash after my oldest brother was walking him, and hauling ass to a house a block down from mine and getting in a fight with two Rottweilers. My brother ran over as quickly as he could but couldn't get a hand in, as the animals were fiercely going at it. Sadly, one Rottweiler died, the other was injured, but not enough for it to die or anything. I'm pretty sure the reason my dog was able to kill one, as that one of the Rottweilers was tied up to a post, putting him at a disadvantage, and both were probably still young dogs not used to fighting. The owner of the 2 dogs, some old lady, came out and threatened to shoot my dog with a shot gun. Accordingly, my brother picked up our pit, and hauled ass out of there when she went inside for her gun( I lived in a small, dirt town in Texas. Probably about 40% of the population, probably about 5,000 in total, there owned a gun) My dog got into a couple of other scuffles, but not enough to kill other dogs as he got older...just enough to maim. Glad though, as my dad got tired of waking up, and finding another dead animal on the lot to clean up after.
Despite his aggressive nature, I still miss that dumb dog though. I missed training him to sit and roll over. Sitting outside next to him at night, just looking at the sky like some ignorant hick. That, or watching him hump his favorite piece of carpet, heh. He died of old age, and probably deteriorating liver to boot. Was sad to see him go.
I've also seen pigs killed, or shot and then eaten afterwards. Seen Goats hung by the hind legs, throats sliced, gutted immediately...and then eaten afterwards. I hate the noise they make when they die though. Sounds like a person dying/screaming at the top of his lungs when they kill it..blegh. Man, that's why I think if there is a heaven, old school Mexicans have a chip on their shoulder of ever getting in. Oh well, I'm sure if that's a case, other cultures are f***ed as well...