well I know we have spoken of this before but this is why we always focus on sterilization as our primary goal. There was a very wealthy couple who established a no kill, no sterilization park of sorts in South America or something like that and they thought that with enough wealth they could sustain this... they were wrong and 100 dogs quickly became 3000 and then disease broke out and the numbers reduced to a low level again. If they had just sterilized the animals they would have eliminated a great deal of suffering that those poor animals had to go through.