Originally Posted by froggy7
If her weight is acceptable, and she is still being playful and active, then I wouldn't worry about it. If dogs are anything like children they probably go through spurts where they need more food and then times when they need less. If she started to lose weight (and that didn't stop by giving her more food), or she starts seeming lethargic, then I would consider getting a second opinion from your vet.
Also, are you getting close to the end of the bag of food? My dog seems to get less interested in food as it gets to the end of the bag, and the interest comes back with a fresh bag. I think it gets a little stale by the end.