IMO - Iams is probably one of the worst brands to feed - It's WORSE than feeding McDonalds everyday for breakfast, lunch and dinner. This company, from what I have read also conducts very horrid animal testing procedures. So that alone is the reason I would NEVER support such a company.
Are you able to find a 'smaller' 'mom and pop' type of pet food store? These are the stores that carry the better brands.
Canidae
Merrick
Solid Gold
Nature's Variety
Wellness
Check out:
www.dogfoodanalysis.com
You want to get a food in the 5 to 4 start range (6 stars is too much protein). BTW I think Iams is a 1 star food - yuck!