Does a raw diet, make your ferret grow bigger? I got my New ferret at 6-8 weeks, and have been feeding him a raw diet consisting of mealworms, thawed frozen mice, raw eggs, ground beef/pork/turkey/chicken, cuts of meat. He is ridiculously big (biggest ferret I have ever had) at only 4 months old. This will be the first ferret I am raising on an exclusively raw diet. ( I am trying to convert my older ones as well) I will see how big he gets after a year, I am really excited for this one!