The fastest way to a bad coat is to wash too frequently, as everyone else has written. So, you'll want to cut it down as suggested.
However, the look of the coat is more about nutrients than it is the shampoo, in my opinion. I feed my dogs raw and fish really makes their coats shine. However, any good quality kibble will do the same. Mine had very nice coats on Canidae, Wellness, Innova, and California Natural.
Conner gets bathed about 2x a month. That's the absolute longest he can go w/out stinking us out of the house. He's not a very good self-cleaner and he loves, loves, loves to pee on himself.
Tess helps him out with the grooming and we use wipes until we absolutely have to wash him. He's a big mess!
Tess gets a bath about once every 2 months, if that often. She's an exceptionally clean dog, though. She is like a cat with her self grooming regimen.
For shampoo, I've been using a cheap Hartz brand oatmeal formula. It's just what I had handy. Nothing special. But, yesterday, I bought Earth Bath Mango Tango. It smells SO good! I can't wait for Conner to pee on himself so I can try it out!
