It sounds like your dog's condition is just right. You SHOULD be able to see a definite waist and be able to not necessarily see, but feel the ribs easily. You could always attach a photo of your dog from the side and looking down (standing up for both views) and get more opinions. You can always give your dog some low cal treats like carrots if they seem to be hungry.
Xan Varik von Fernheim (born 4/3/13)