@jerry It could be the the dog isnt getting something she needs from the food anymore, and is instinctively rejecting it. I would check with your vet before parading a new line of dogfoods to the pooch, but its a possibilty.
Could also be that she's just not hungry. Our dogs kinda graze on their food all day, and dont eat it all at once, We've resigned outselves to the fact that they eat when theyre ready.
when i had shared custody of a pug who got moody and didn't always eat, i discovered that purina kitten chow is like crack to dogs. 3-4 pieces put on top of his food usually worked.
i will warn you. he did decide that those were mandatory and would wait, just staring at me until i put them on his food if i hadn't already. ;)
yeah... part of the challenge with the pug was that he was on weight loss food, which he did *not* like... i figured that 3-4 pieces of kitten chow wasn't even a mouthful but got him motivated.
fingers crossed you find the right combo for your puppers.
I had the same problem with at previous dog and solved it by sometimes "seasoning" his kibble with just a little bit of crumbles of dry bread. Most dogs I know love dry bread.
Later I ended up with a rather funny routine:
After he was done: "come on, let's have a look!" and either in a very playful way "O that's a good boy!" and gave him a small treat, or in a very sad voice "oh no... it's not finished..." and then he would finish it most of the time, just to get the treat.