My lab mix was picky about her food after I gt her, which is rare for a lab. I didn't know any better and was feeding her pedigree puppy, which was actually a step up from what she had been getting fed. I tried wetting it it down, adding broth, adding canned food. She'd eat some and then leave it. I ended up buying a small bag of Earthborn puppy food at my local feed store just to give it a try. She ate it all no problem, and never had an issue finishing her food after that.
Iams is not known for being a high quality food. I checked out the ingredients:
Chicken, Ground Whole Grain Corn, Ground Whole Grain Sorghum, Chicken By-Product Meal, Corn Grits, Brewers Rice, Dried Beet Pulp, Fish Meal (source of fish oil , Natural Flavor, Fish Oil (preserved with mixed Tocopherols), Chicken Fat (preserved with mixed Tocopherols), Dried Egg Product , Dried Brewers Yeast, Potassium Chloride, Caramel Color, Salt, Choline Chloride, Calcium Carbonate, Carrots, Tomatoes, Fructooligosaccharides , Spinach, Minerals (Ferrous Sulfate, Zinc Oxide, Sodium Selenite, Manganese Sulfate, Copper Sulfate, Manganous Oxide, Potassium Iodide), Green Peas, L-Lysine Monohydrochloride , DL-Methionine ,Vitamins (Vitamin E Supplement, Ascorbic Acid, Calcium Pantothenate, Vitamin A Supplement, Biotin, Thiamine Mononitrate (source of Vitamin B1), Vitamin B12 supplement, Niacin, Riboflavin Supplement (source of Vitamin B2), Inositol, Pyridoxine Hydrochloride (source of Vitamin B6), Vitamin D3 Supplement, Folic Acid), Dried Apple Pomace, Dried Blueberry Pomace, Mixed Tocopherols, Rosemary Extract.
Chicken is the first ingredients, but that is deceptive because raw chicken contains about 80% water, so once that is removed during the cooking process it would drop much farther down on the ingredient list. So the first ingredient by weight is actually whole grain corn which is an inexpensive grain and of questionable nutritional value and most a filler. Sorghum falls along the same lines as the corn, a starchy grain filler. Chicken by product meal is a dry rendered product of slaughterhouse waste. It’s made from what’s left of a slaughtered chicken after all the prime cuts have been removed. This actually contains more protein than the raw chicken listed as the first ingredients since it is concentrated, but is still a lower quality, inexpensive protein source than chicken meal(I only select foods with a names meat meal as the first ingredient). Corn Grits, Brewers Rice, Dried Beet Pulp are all more inexpensive fillers, not things I like to see that high up on the ingredient list.
All in all you are feeding a grain based food containing a low quality protein source. I would not be surprised if she showed more interested in eating a better quality food.