The Ferret:

Domestic ferrets (Mustela putorius furo = mouse-eating smelly little thief) are in the Order Carnivora and in the Mustelid family. They are related to otters, martens, minks, badgers, skunks, and more. There are three species of ferrets; the European polecat, the Siberian polecat, and the black-footed ferret (currently on the endangered species list). 

Ferrets are strict obligate carnivores, sometimes even referred to as super carnivores, meaning they are adapted to eating a strictly carnivorous diet. 

 Ferrets require a highly concentrated diet that is high in protein and fat and lower in carbohydrates and fiber. The only carbohydrate source in a ferret's diet should come from its prey's gut contents. Fat, when metabolized, releases twice as much energy as carbohydrates or proteins and therefore should be the main source of calories in a ferret’s diet.  

Ferrets have 34 blade-shaped and precisely interdigitated teeth that are designed kill prey, shred meat from bone, and break down small non-weight bearing bones. 

A ferret's GI tract is essentially a short tube from their stomach to their rectum with an average transit time of 3-4 hours. Due to this short transit time, food passes too quickly for efficient absorption. Thus, a fully digestible diet is a must. 

Unlike dogs and cats, ferrets naturally secrete hydrochloric acid which not only aids in digestion but also creates an acidic environment that does not encourage bacterial overgrowth.

Ferrets also require three times more water than dry matter in their diet, thus offering fresh and clean water in multiple ways is a must. Raw feeding also allows the ferret to get more water intake than that of a dry kibble diet. 

Because of their anatomy, physiology, and behavior, a raw diet is best suited for the ferret. 

Source: Kohles, DVM, MPA, M. (no date) It's a Gut Thing - GI Anatomy, Physiology, & Nutrition of Exotic Companion Mammals, 2/2: Ferrets, Hedgehogs, Hamsters, Rats, & Everyone Else! (EX36), VIN. Available at: https://www.vin.com/members/cms/project/defaultadv1.aspx?pid=24703&catId=&id=9514126&said=&meta=&authorid=&preview= 

Why Raw? :

The domestic ferret is still marketed to consume dry kibble, yet these diets contain a higher than recommended level of plant matter/grains to maintain the kibble's integrity and nutritional value. (If you don't know how kibble is produced, I highly encourage you to visit my Diet Talk page. 

Due to their short GI system, ferrets are unable to fully digest ingredients in kibble. The carbohydrates in kibble are an unsustainable form of energy for the body, which is why ferrets should never be fasted from kibble longer than 3-6 hours, with an insulinoma ferret requiring more frequent feedings (every 1-3 hours) to avoid hypoglycemia. Visit my page on Insulinoma to learn more.

Due to their dentition, studies have shown that kibble-fed ferrets secondarily develop dental wear and disease due to performing the grinding mechanisms required to break down kibble. 

If the provided information about your ferret's anatomy, physiology, and nutritional needs is still leaving you with questions, let me tell you what I tell all my clients:

• The most common results of feeding commercial kibble is diet-induced insulinoma. 

A ferret's pancreatic beta cells become overloaded with the excessive amount carbohydrates from kibble converting into glucose. After a prolonged amount of time, the beta cells will become overactive to keep up with the insulin demand. This constant demand for insulin results in a complete burnout of the beta cells (similar to diet-induced diabetes in humans) and will likely convert into neoplasia (cancer = Insulinoma).

I have seen incredible results with my insulinoma rescue ferrets converting to a raw diet. Some are able to come off of their medications completely, or with those too far advanced, at least a decrease in the amount and frequency of medications. 

When you feed a balanced raw diet to your ferret(s), you are ensuring that you are providing them with the best possible dietary and health care, and possibly even extending their life. 

Source: Kohles, DVM, MPA, M. (no date) It's a Gut Thing - GI Anatomy, Physiology, & Nutrition of Exotic Companion Mammals, 2/2: Ferrets, Hedgehogs, Hamsters, Rats, & Everyone Else! (EX36), VIN. Available at: https://www.vin.com/members/cms/project/defaultadv1.aspx?pid=24703&catId=&id=9514126&said=&meta=&authorid=&preview=