Thanks for the savefile, @Sherlock_Rose.
Is there a way to reproduce this consistently? We’ve tried the steps from the OP but they pets are fine.
In the savefile from Sherlock_Rose, the pets are away from town but it would be nice to know how did it happen.
Did the host save while the client was connected or disconnected? Did the host save/load several times? Did the issue start to happen after the first reconnection from the client, or at a later reconnection?
It’s very confusing because this bug is supposed to be fixed since the build after r887 (we’re currently in r893) 
: [r887] Pets and shepherded animals are "away from town" after rejoining multiplayer server