I also feed the Salmon and Potato to my lab. We started her on in back in September, a few weeks after we got her, and she loves it (that said, she’s a lab and loves everything semi edible). Within a week or so, her coat was shiny, bald patches grew in, and she started gaining weight. We’ve slowly gotten her weight up (she was a rescue and needed to put on about 10 lbs) and have recently decreased the amount of food she gets to maintain her weight. Regardless, she looks wonderful.
My other dog is on Blue Wilderness and is doing great on it (that said, she gets >1/2 cup 2x/day so a 24lbs bag lasts months). We went with the 4Health because the Blue just wasn’t in the budget for the new dog, especially when weight gain was a goal. For the price, the 4Health was a decent enough food. New dog also had skin/coat issues (she had been treated for mange at the rescue, and she still had missing hair and dry, itchy, flaky skin) and I wanted to try and fish protein. All issues cleared up on this food. Is it the best food out there? No. But it’s working for us.