My dad and I were helping out a family friend by setting up glue traps around their house to try to kill kangaroo rats that were eating their AC insulation. They were poisoned so that eventually the rats would die, but when we went to go check on the traps one day we found a rat that was still alive. He decided that we should put it out of its misery, but all we had were BB guns, the pressurized CO2 cartridge ones, not spring loaded. I shot it with the first BB and it was still alive, but after the second it died. First mammal I killed and I felt pretty horrible about how much pain I must've caused it. It's irrational to assign that much sentiment to one species when I've watched snakes and insects die all the time out here in the desert, but I don't know, I just felt shitty killing something that looks like a household pet.
I'd say you're normal OP.