I have a 5-6 yr old male who weight a little less than 11 lbs & he get 2/3 cup dry w/a little wet once a day. Our 4 yr old female weighing about 8 lbs get a little less than 1/3cup w/wet 2X a day. Both are rescue dogs/male we've had for 18 months-female since June this year. The male poops usually 2-3X a day/the female 3-4X a day, both get the same food. I was surprised by the info on dry dog foods & will look into "Chicken Soup", Artemis or Innova. I do feed them 2 mini-carrots a day, but may try some canned salt-free green beans instead. I'm not worried about their weight, just the nutrition. Thanks again for the info.
I wonder if the wet food could be making them eliminate more... If you are feeding top of the line food they should be getting all the nutrition they need. If you feel they might need more, you could give a complete daily vitamin-mineral supplement.