One of my cats is a stray that someoen just dropped off here. We live in a cul de sac sort of neighborhood at the edge of town and for a long time people used to drive up to the end of the road and drop off their stray cats. I'd be in the kitchen, hear a scratching at the back door and it would be a new stray. I've placed dozens of cats in homes that just showed up one day. Right now we have a pure white cat with the silkest fur, just showed up at the door like the rest. She's very sweet, constantly begging for affection and petting, fixed and I've advertised her in the paper off and on for nearly a year and no one wants her. I don't understand how anyone could have dumped her because she is just so loving. People make me sick.
Oh, and Ice Queen, Petsmart and Pet Co do kill off their sick birds instead of treating them. I know this for a fact as a bird rescue person. Several of those parakeets came from one of those stores.