Figblat and RandomLilTurtle Thanks for your tips on getting the missing animals back in their households. I checked my current saves and found 3 families whose pets were missing. But I was able to restore them to their owners. It was a tedious process and doesn't solve the problem in new saves, but at least it rescues these pets.
This is the process I used, but there are other ways to do the same thing.
The first thing I did was use a random sim in CAS to add the missing pets to temporary households, then saved them to My Library. I found Mayor Whiskers and Captain Whitaker in the Gallery. For the regular animals, I used pets from one of my saves that still had them in game. All are now saved in My Library.
Then I went into Manage Worlds and temporarily placed the random sim with each world's animals (Chestnut Ridge and Brindleton Bay). I used household management to transfer the pets back into their proper households. After that, I just deleted the temporary random sim.
For the strays, I was worried about releasing them into Brindleton Bay again as strays, so I added them to families living in Brindleton Bay (usually Hecking and Lynx).
All the animals are now back with their rightful owners.
For those who don't want to go Gallery hunting for the premades, SrslySims has all of the EA households uploaded to simfileshare to go along with her blank save: https://simfileshare.net/folder/53349/
Of course, since Mayor Whiskers and Captain Whitaker don't have humans in their households, the game won't let you place them unless you put them with a human, so I don't think there's a way to get Captain Whitaker haunting his beach again properly. :/
flying-womrats Thanks for that link. Very handy for future needs. I added it to my browser's favorite Sims 4 links. 🙂
