Ferrets are now domestic animals, but the natural diet of their wild ancestors consisted of whole small prey, such as small rabbits and birds. Ferrets need to eat frequently because of their short digestive systems and quick metabolism.
Ferrets are often mistaken by pet owners as rodents, which are omnivorous, but they are actually mustelids. Ferrets cannot withstand plants in their diet because they do not have a cecum in their digestive track and are largely unable to digest plant matter. They have a very short intestinal tract, and food passes through the intestines in about 3 hours. Ferrets must eat highly digestible and concentrated food to allow for the short digestion time. The food ferrets eat must also be high in animal protein and fat to help maintain a healthy immune system.
As long as ferrets have enough fat and protein in their diet, they have no need for carbohydrates. Having too many carbohydrates can cause insulinoma, a tumor of the pancreas, and diarrhea in ferrets. Taurine, an amino acid found in meat, is vital for the heart of a ferret and essential for good eye function. If a ferret does not have enough taurine in their diet, their heart muscle could stretch and become enlarged. This can lead to dilated cardiomyopathy, which may result in congestive heart failure and death. Ferrets imprint on their food at around six months old, and older ferrets do not eat foods they did not eat when they were young.