It’s going to be hard to find a food that has THAT few ingredients
CANINE DRY:
Potato, fish meal, animal fat, dried beet pulp (3.9%), fish digest, dicalcium phosphate, calcium carbonate, sodium hexametaphosphate, fructooligosaccharides (0.39%), potassium chloride.
There are a few companies that make LID diets that are fish and potato based.
Merrick- Salmon& Sweet Potato
Natural Balance- Fish & Sweet Potato
Zignature- Trout & Salmon
Wellness Simple- Salmon & Potato
These foods are all available on chewy.com if ordering online is something that could work for you. You can also take a look at their full list of Limited Ingredient Diets here and see if another might work better for you: http://www.chewy.com/dog/dry-food-294/limited-ingredient-diet,FoodFlavor_facet:Fish
I already filtered it to only show fish based foods. Best of luck!
