Thanks to every thing food related needing a label giving all the ingredients with a quick search I found this.
McDonalds fish
http://www.mcdonalds.com/app_controller.nutrition.categories.ingredients.index.html
Fish Filet Patty:
Pollock or Hoki, bleached wheat flour, water, modified corn starch, yellow corn flour, salt, whey, sugar, dextrose, dried yeast, disodium pyrophosphate, sodium pyrophosphate, sodium tripolyphosphate, cellulose gum, colored with extractives of paprika and turmeric, natural flavoring (vegetable source). Cooked in partially hydrogenated vegetable oils (may contain partially hydrogenated soybean oil and/or partially hydrogenated corn oil and/or partially hydrogenated canola oil and/or cottonseed oil and/or sunflower oil and/or corn oil). Contains wheat, milk and fish (Polluck or Hoki) ingredients.
Burger King: Big fish
http://www.burgerking.co.uk/pdfs/ingredients.pdf
Fish patty
Alaskan Pollack, Breadcrumbs, Water, Potato Starch, Modified Potato starch, Modified Maize starch, Wheatflor, Salt, Yeast, Raising Agents: E450, Diphosphates, E500, Sodium Carbonate, Dried Hen Egg Powder, Sweet Whey Powder, Vegetable Oil, Stabilizers: E472c, Citric acid Esters, E300, Ascorbic Acid.