Sometimes there is nothing you can do to prevent a tragedy. We lost 3 of our bottle baby kittens to illness. Zig, the smallest, went first. Then we thought Cuddles was going to go, she lingered in limbo for awhile; she eventually pulled though. But as she pulled through both Socks and Buffy went down for the count. There was nothing we could really do for them.
Right after that the 4 new kittens from Momma Kitty (Dolly) got sick, too. They were just too little to fight it off.
One of our early spring kittens, Jack, developed some problems and had to be put down, also. And right after one of my hens got sick, and died, apparently of congestive heart failure.
We have had more kitty funerals this summer than my poor heart can stand.
To top it off just as I was thinking everyone's health was looking up, and we were finished losing kitties, Max, the Cockatiel, died too. I swear he waited until I just could not take anymore tragedy and then committed suicide. Max is still in a baggie in the freezer. I just have not been able to face digging one more hole and burying one more animal.