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
This has been happening to me for a long time. Now the overspawning festivals have gone this is next worse problem. I just need to click on the barn or coop now to restock and grim appears before I even populate. He even takes chicks. They all say one last pet. I play with no mods ( normally) I do occasionally install MCC but only to correct a bug. I'm happy to supply a save.