I'm pretty sure they do. I had emailed them a few months ago and they never replied (asking if any of their foods were made at Diamond).
But some of their formulas are made at other places. Their Synergy food is made at CJ Foods.
Here is another list manufactured at Diamond:
Diamond Pet Products
Diamond
Diamond Naturals
Artemis Pet Care
Canidae
Chicken Soup for the Pet Lover’s Soul
Premium Edge
Taste of the Wild
Professional Pet Food
Natural Balance *
Solid Gold
Wellness *
Eagle Pack *
Holistic Select *
4Health
Country Value
Kirkland
* = also has foods manufactured at other plants |