Sadly healthy animals are put to sleep because there are far too many and nowhere for them to go
I personally don't put any healthy animals to sleep, I have had them pts through health problems where nothing else can be done for them, I do my best to get them sorted but sometimes this isn't always possible.
If people got their pets spayed and neutered, the problem wouldn't be half as bad as it is and rescues wouldn't be overflowing to the brim. I also think sadly for some, it's a lottery whether they live or die........the youngsters will have more of a chance of being saved but I know of young kittens etc that have been euthanised because there is no room for them......this is a sad fact of life
Area wise, I think most are pretty much the same.......there is a problem everywhere