Bizzare dog behavior

My mom has two pomeranians. For years she's fed them the same dry dog food and the dog food she feeds them has 2 different shapes-a ball and a bone. They both ate it for years with no problem. Then one day, one of the dogs, Princess, decided she just doesn't like the bones anymore, and will sit there in front of her dish and scoop out the bones with her paw and eat only the ball shaped peices. The other dog Sugar (who is Princess's mom) eats both of them still, but I won't be surprised if Sugar starts eating the bones only and Princess eats the ball shaped peices. lol

There is no real logical explanation, or so it seems from the description you offered, of why she no longer eats one of the shapes. Maybe a bad experience, who knows! Watch her and make sure this does not progress.

That's very strange! Mabye, she just got tired of it after all these years? Mabye they changed the flavor to one she hates? Check the box and make sure she eats something!

Try adding a little Chicken broth to her food and she will dive in and eat it all!!!! ;) :D