What brand of food should i feed my chihuahua?

Science Diet, Eukanuba, etc are really not healthy foods. And a dog on the right diet frequently will not ever need to have their glands expressed. Try going to www.dogfoodysis.com and looking at their dog food ratings. They rate almost all the dog food out there, and tell you why it is or is not good. Try to stick with one in the 5 or 6 star range, those are the really good ones.