It's hard to decide what's sadder at an animal shelter—the dogs or the cats. Cats are more mental—they lay around with grim, hardened expressions seemingly thinking something like, "I can't believe my life has been reduced to this, I'm so above this squalor and all the assholes who walk by gawking but don't take me home with them." However, the dogs peer up at you with eyes that are deep pools of sweet sadness and you feel bad for them because they probably don't know that they're never gonna get adopted.
Um, anyway, spay and neuter your pets, people! Okay, that's all.