Penguino's Animal Immortality Hack Issues

[guitarbirdb]

I've been working on a zoo for some time, and I noticed that my horses keep dying out easily. I tried downloading Penguino's Animal Immortality Hack and took in mind this notice: 

 

"Note: Please put the .ztd file in the dlupdate folder, not the updates folder. Not compatible with the DD attractiveness boost hack."

 

However, I'm still having issues with some of my animals dying easily. What could be causing it not to work? My animals are in good care too. 
Does this only work for zoos you're just starting out on? Is there another immortality hack that might work on an older saved game?

[Fern]

It would most likely only work for ingame animals. And it would also depend on when he made it as to what ingame animals

[guitarbirdb]

Do you know if there's anyone who would be interested in making one for downloaded ones, or is that kind of hard to do?

[guitarbirdb]

Or is there a way to modify the files so certain ones live longer?

[Fern]

It would involve editing individual files and I have found that somewhat time consuming.