I started NV by giving my boyz about 1/4 of a medallion for a treat for a couple of days and slowly went to a full madellion from there. There was no stomach upset or anything...no gas or smelly pooh either.
We do leave dry kibble out if we're going to be gone past their mealtime but the NV is a complete food and you don't need to feed anything else. My boyz rarely ever go to the dry food bowl and most days I only leave fresh water down.
The amount you feed depends on the size and activity level of your dog. You can use their feeding chart on their website:
www.naturesvariety.com and it will tell you how much to feed. My boyz are both about 4 pounds with a moderate activity level so they each get 1 medallion for breakfast and one for dinner.
You will se a big difference in her stool. Once she's on the NV raw she won't go as much and when she does it will dry, turn white and blow away. They use everything from this food so there isn't much to waste.
My boyz love their NV and I've seen some wonderful changes in Jo since I switched them so I'm sticking with it.