Wow...I'm so excited to be able to offer some kind of input so early on as a member here!
I will start by saying (since I'm new here and it isn't YET obvious) that I am a BIG advocate of very smart nutritional choices for our animals. I read ingredients, research healthy choices, and firmly recognize the link between excellent nutrition and excellent health.
That said....
I am presently feeding Wolf King by Solid Gold to Balthazar and went through a LOT of thinking and research before choosing it. When I got him from the rescue org, he was eating Nutro Ultra Large Breed Puppy food. In researching (and I'm sure the experienced people here can offer MUCH more knowledgeable feedback on this part), I continued to get guidance to feed Balthie a NON-PUPPY formula because the increased protein and fat could cause undue stress on his joints, leading to later health problems.
I ultimately oscillated back and forth trying to decide between Wolf King and Taste of the Wild. I went ahead and offered the Wolf King by transitioning it into his bowl, and Balthie is doing GREAT with it and he also really, really enjoys his food. He's no longer on the Nutro...he's doing Wolf King alone. I love that it is a very lean choice, that the ingredients are corn and by-product free, and that it's a bison & salmon based formula rather than chicken/turkey.
I, too, am not 100% confident in knowing it comes from Diamond, and may make a change at some point to Taste of the Wild (AND may post my own questions about food as well).
I just wanted to let you know that as far as the food itself goes right now, it is a very good choice for Balthie's enjoyment and the nutrient content appears to be top notch, IMHO. Maybe we can continue to "talk it out" here and gain wisdom from one another r.e. the Diamond concern.
Sorry I couldn't be more 'decisive' in my thoughts or opinions but maybe just talking about it helps!
Love,
Jen