Well, I used'ta feed em NutroMax for Active dogs. Breeder recommended it.
But now that Penny (7yrs) is entering middle age and Gordons have a knack for developing crystals in their urine, I feed her an Rx food from the Vet. If anybody knows another food that reduces the crystals I would be game. The Rx cost about $40/month. She's worth every cent though.