Ugh I bet the flies have a good feed as well jj. Doesn't sound very hygienic. Vet advice is to feed dogs morning and evening and to put food down for half an hour and if not eaten remove it and throw it away, especially if it is wet food. And that is assuming the food is kept inside the house. I don't think I would throw it away if it was hard food though. If they eat twice a day you get to know when they will need to go out to do their business as a pattern will form. Makes life easier for you. Better than if they are grazing all day. My dog eats his food so quickly there's no chance of any other creature getting a look in and if a fly came near the dish he'd eat that as well. Just a bit of unasked for advice jj, sorry, I can't help myself:-)