TOTW Wetlands.
I feed it because it's grain-free and I feel like my pups are active (and young) enough to handle the higher protein. They also get fresh fruit and vegetables along with treats.
They were on Pedigree Puppy (I think) until 6 months or so.
That said, I've also tried them on other TOTW flavours, Solid Gold, Chicken Soup for the Puppy's soul (I like this), some kind of raw dehydrated stuff, and Instinct. Nearly everything but TOTW has been way too rich, a higher protein level than i'm comfortable with, or they've completely snubbed their noses at it.
The main reason I keep them on Wetlands is because they love it and it seems healthy for them. They ate the High Prairie flavour for probably 5 months, then we tried a rotation to pacific salmon. They hated the salmon and seemed almost lethargic. :\ So I put them on Wetlands and they're full of energy. It seems to suit my dogs well.
