Sorry about your upsetting news about the kitties. They are just like part of the family and I know you are worried about them.
I know how you feel because I have a dog that's almost 13 and has been having problems breathing out of his nose. The doc took X-rays and couldn't find any growths in his nose and is very puzzled. We are just going to try and love him as much as we can and keep him as comfortable as we can and enjoy every moment with him.