I got a sample of Merrick puppy food and Lucy loves it. She was not eating well & hadn't gained weight in a month so I'm trying different food and she loves the Merrick and Orjien. I thought I had read that with the Merrick to mix water in it to make a gravy but I don't see anything on the bag. I poured some warm water in the bowl but there wasn't any gravy. Should I be adding water to the food or something else? Thanks!