This is an open bug that was archived. I am not sure if a new bug report is meant to be made.
Animal aging is turned off in options. Aging is turned off for all sims.
I have a save file I have p...
Ideas
Just happened to me as well. Looks like all animals aged when I was not playing the households. Despite the setting being turned off.
This is rather dark. Rip Harold, my lovely lama.