The greys all eat Nutro Natural Choice Lamb and Rice, and we are happy with their health, coat, 'output,' etc. Pup gets Nutro Max Weight Control and salt-free canned veggies.
Buddy recently started walking aaway from his meals when they were only about half done, so we started giving him half his food and half Pup's food. Now he eats every bite! I guess that, after a year of the same food, he lost interest and wanted some new taste!