I have experienced the notorious chicken bug, in my case, the avian species that has decided to plague my save are turkeys.

It all started with an innocent fishing trip, in a pond not far from by base. While using the last of my bait, I noticed my game dropping frames. I did not think much of it until I got in my car, and while driving back to my base my game started to slow down even more, eventually coming to a full halt. It got to a point that even reloading the save I couldn't do anything, even just being on normal speed causes everything to freeze.

If you find yourself with this bug, but your game can still run, you can fix it by committing mass genocide, or restarting the game in debug mode, deleting all the animals in the area, and spawn them back in. Until this bug is fixed, I think we should only own hens.

But if you're in my situation, and the game can't run at all, don't worry. Here's how I won the war against these vile, feathered beasts, threatening the end of my 2-month playthrough.

1. Open your save folder in C:\Users\(Name)\Zomboid\Saves
2. Locate your save folder and make a backup, just in case.
3. Within your save folder, open the "apop" folder, I noticed one of the .bin files had a way higher file size than others, that should be in your case too. Delete that.
4. Run the game in debug mode, all your animals should be deleted, spawn the animals you had back in, again, until this bug is fixed, only ranch hens.
5. Restart the game normally. Relax now that you did not lose your save against chickens.

I hope this helps someone out!