I've found that this occurs when the sims return from any lot not just restaurants. On leaving the home lot the dog was clean, on returning the dog is filthy. This only happens if all households sims have left the household lot but I have still to test with leaving toddlers and children on the home lot with the pet while the other household members travel away.
Hi @NZsimm3r and @Hi_its_Nobody
how long do you stay away ? I wasn't able to duplicate with the lot I tried but only stayed very briefly. Haven't tried a restaurant though.
Only one Sim at my lot though.
I'm usually gone for like 6 hours since my sim is running the restaurant but yeah.
I'll do some more testing and stay longer then. Won't have time before the weekend though
