As for the basic feed I would recommend a high protein/high fat feed, . And that is especially true the more work a dog gets. Studies have shown working dogs on a high protein diet have less soft tissue injury. Look for food that the first few ingredients are meat or meat meal. Supplement with a high quality fish oil capsule that is pharmaceutical grade/molecular distilled with a EPA to DHA ratio 2/1. Plain yogurt or kefir is also good for a dog. And a MSM and Glucosamine capsule as well.
I feed Evo a 42/22 feed. I also train A LOT. It is not cheap but meat cost more than grains. You get what you pay for. Those that don't have dogs that get a lot of work 28-30 % protein should be enough.

I had been using Canidae for a couple years, then they changed the formula w/o telling anyone. Google the complaints and you'll see what I'm referring too.

After a quick but extensive search (before my bag of old Canidae ran out) I switched to Innova.
http://www.naturapet.com

Diamond

Had the same problem with Canidae. They changed the formula and he had loose stools. Now I feed him Nutro 30/20.

Best dog food for my Lab Im my opinion is

http://www.tasteofthewildpetfood.com/

I feed Purina pro plan. It's pricey but you should see my dog's coat. Everyone comments on his coat.

30/20 ratio and the number 1 ingredient is corn.

I too feed Purina PRO-PLAN but only with 2 other dry dog foods! I just don't trust the dog food companies 100% anymore. Especially after what happened a couple years ago with the DIAMOND DOG FOOD COMPANY...YIKES!!! OVER 100 dogs died from their tainted dog food and they tried to LIE their way out of the problem, saying it was only an isolated incident.

YEP, isolated in 23 frigging states folks, I almost lost 6 dogs over that deal but lucky for me I only gave them 33% of the product mixed with other feed. NO MORE DIAMOND!!!

Let the dog be your guide.

Some dogs thrive on some food that would render another dog low.

My lab pup thrived on Iam's Large Breed Puppy food till it was a year old. It now (believe it - or not) thrives on Wal Mart "Old Roy"! No gas, no runs, great coat, great teeth etc.

Don't judge a dog food by what you read in other dog food company's ads.

Brian I use Ole Roy and mix it to a ratio of usually 25% with my other brands of dog food. I been feeding that feed for over 20 years now and it has always been very stable as far as the dogs doing good on it etc.

Hunters Special is another feed I use to help keep the weight on the dogs throughout the years. Our dogs get exercised at least 2 hours every day unless it is storming outside. Excell is another all chicken product that is very good for hunting breeds, at 30%protein and 20% Fat.

I meant, the number 1 ingredient is CHICKEN. Duh.