We had this problem towards the end of our last shepherd's life. She unknown to us had a tumour on her spleen so I don't want to worry you but I would suggest asking your vet for another checkup. The tumour was only detected through a scan. There was no other sign prior to that other than being reluctant to eat her food (but not treats|) and sadly it was so advanced the only option was to have her put to sleep straight away. I so hope this isn't the case for you.
I would think that if you are leaving her food down for 12 hours it becomes rather unappetising. The advice I've had in the past is to pick it up if not eaten within the hour though I confess I've never been able to follow it, too soft hearted. Perhaps as an elderly lady she likes a varied diet and 'little and often'. I have always fed my current rescue GSD, who is now 12 1/2, on Lily's Kitchen. It's not cheap but the ingredients are good (Prince Charles feeds it to his dogs!) and I give her something different every meal and every day. She loves it and eats every scrap. Plus a few treats of course and a special meal of freshly cooked chicken or beef once a week, her Sunday treat. Good luck!
: What has been your most wasted purchased made in preparation for a holiday?



