I am now experiencing this issue in my current save.
My current save is a clean world save where I am building or adding in gallery sims/homes.
The dog spends all it's time in front of the fireplace and did so at two different homes.
At one point he did not eat or go outside. He randomly gets dirty.
I would love to know what the fix is. I prefer not to turn off the fireplace outside of the summer/hot weather seasons.
TYIA. I am testing with and without mods but it's frustrating b/c I keep having multiple bugs/glitches that are often not related to any mods yet I have to stop playing the game to try to figure out how to fix these problems. I really think that is unfortunate and ruins gameplay. I get if it's mod related then it's my own fault but most of the worst issues in the game are not related to mods/cc. I am also careful what I add to my game and keep it at a minimum most of the time for any mods I do use.
This particular issue is a gameplay interference however.