In recent months, numerous people have asked I discuss a number of issues regarding ferret diet. For several reasons, I have been unable to respond to the requests until now. For this discussion, I will mention 10 ideas that are widely held, but generally mistaken. I don't have time to explain questions that may be answered in follow-up posts, so if I think a remark or question may be answered later, I will ignore it. After I post the final part, I will happily answer those questions that were not discussed. I will supply a bibliography when finished. ------------------------------- Ten Myths regarding Ferret Nutrition: 1. Because ferrets [polecats] eat the intestines of prey animals, carbohydrates are a natural part of the ferret's diet. FALSE. It is true that ferrets will eat the intestines of small rodents, but they may or may not dine on the bowels of larger prey animals. Polecats/ferrets tend to eat the head first, followed by internal organs and muscle meat. This general sequence of carcass consumption insures the best parts (generally the most nutritious) are eaten first. Why is the head usually eaten first? Brains are full of the essential fatty acids, fats, and proteins a primary, obligate carnivore like the ferret needs the most. By the time a ferret gets around to eating the intestines of larger animals, many free carbohydrates have been fermented by intestinal bacteria, or the bowel has already decayed to the point only a starving animal would try consuming it. Even if you added the bowel contents to a ferret's diet, the relative percentage would range somewhere between 1-5% of the diet. Compare this to 40-60% carbohydrates found in the typical dry, extruded diet (kibble). So even if 1-5% carbohydrate is naturally consumed, that is VASTLY different compared to what they eat when crunching kibble. Another important aspect of ferret diet is the type of animals they eat. Wild European polecats are anuran specialists, especially during the winter months. Adult anurans -- frogs and toads -- are also carnivores, and lack significant carbohydrate within their bowels. While small rodents (rats, mice, voles) and lagomorphs (rabbits, hares) are an important aspect of diet, polecats also eat insectivores (shrews, hedgehogs, moles) and birds. Many of these animals are not in the best of shape; carnivores tend to prey upon the injured, old, sick, and starving. Marginal animals cannot be depended upon for bowel carbohydrates. It is clear that a reliance upon herbivore stomach and bowel contents for carbohydrates would be, at best, foolhardy; the ferret would never be able to depend on any significant amount of carbohydrate from the intestines of their prey. Ferrets are primary, obligate carnivores, meaning they PRIMARILY eat animal tissue, and they are OBLIGATED by nutritional requirements to do so. They are not just carnivores, but carnivores that have specialized in only eating flesh. As a part of this dietary adaptation, ferrets have the unusual ability to completely synthesize their energy needs from proteins without suffering the toxic side effects of ketosis (systemic or metabolic acidosis, sometimes called ketoacidosis). While this trait isn't unique among carnivores, it only exists in those that shun consuming significant amounts of plant material (generally less than 5% of the total diet). This abandonment of herbivorous materials is reflected in the extreme simplification of the ferret's gastrointestinal tract. It is so well adapted that the ferret lacks a caecum, or even a visible junction between the small and large intestines. In other words, the ferret's stomach and intestines are so modified to digest flesh that it has lost the ability to digest significant amounts of carbohydrates. The contents of the intestines contain nutrients far more important than carbohydrates; vitamins and vitamin precursors, especially the B vitamins and beta-carotenes. The B vitamins are required to maintain healthy blood, and beta-carotenes are Vitamin A precursors required to replenish visual purple in the retina, among other things. Consuming parts of the gastrointestinal tract is important for ferret, but not for obtaining carbohydrates. These pieces of evidence (diet habits, anatomical adaptations, physiological adaptations) suggest carbohydrates are an insignificant aspect of a ferret's diet. There are other adaptations, but these alone suggest the inclusion of large amounts of carbohydrates in the ferret's diet is inappropriate. Bob C [Posted in FML issue 3937]