Ferrets are carnivores, obligate by nature. This means that they have evolved and biologically are meant to gain their nutrients from other animals.
While there are some studies on the diets of wild polecats and feral ferrets that indicate the presence of small amounts of plant matter, mostly berries, in their digestive tracts, these findings can probably be attributed to the mustelids’ natural sweet tooth and scavenging nature – if prey is unavailable, they may snack on berries to get by. Wild mustelids probably also ingest pre-digested plant matter in the digestive tracts of their prey. While many ferret owners who feed whole prey to their ferrets report that their ferrets don’t always eat the intestines of the mice, rats, and chicks they are fed, some ferrets do eat them and it seems to vary meal to meal. These ferrets are probably either avoiding colons with feces in them, or are not in need of the fibrous material at that moment.
Another explanation could be that since many whole prey feeders tend to feed other foods, whether commercial raw, homemade raw, or kibble, the ferrets are probably already getting the trace amounts of plant matter their bodies are looking for through those other foods.
Personally, my kids rarely ever eat the entrails, and usually leave them. This might also be due to the fact that they are well-fed, and feel they can ‘waste’ the undesirable parts of the mouse, rat, or chick.
However, there are some companies out there that promote feeding dogs, cats, and ferrets a completely vegan or vegetarian diet. These diets are extremely dangerous to our carnivore friends. Even dogs, who are arguably more omnivorous, still do not thrive unless they get meat in their diets. The diet I was just shown by a friend of mine that sparked this blog post is called the Evolution Diet. Here are some of the reasons why these meatless diets are so dangerous to our carnivorous ferrets:
1. Meat is easy to digest. Think about what digestion is: it is the breaking down of foods into smaller and smaller particles, which are then transferred through the intestinal wall and distributed into the rest of the body. Digestion is not the same as consuming something and having it pass out the other end without causing major, obvious damage. Digestion is the utilization of those foods consumed, by breaking them down so that they nutrients can be absorbed. Plant matter takes quite a bit more “hardware” to be able to break down enough to assimilate through the intestinal wall. There are three main reasons as to why ferrets (and other obligate carnivores) cannot break down plant matter well enough to truly digest them. 1. They have very short digestive tracts, which means they do not physically have the time from input to output to break down plant matter. 2. They have no cecum, an organ of the digestive tract of herbivores that contains large numbers of gut flora and bacteria in order to ferment and break down plants. In carnivores, the cecum is either extremely reduced in size and vestigial, or is replaced by an appendix. 3. The natural gut flora of carnivores is significantly different both in amount and makeup than that of herbivores. This is simply because carnivores do not need to utilize the fermentation process herbivores must use.
2. Proteins are basically long chains of building blocks called amino acids. There are 21 amino acids. Humans and dogs need to consume 10 of these 21 in order to survive (called “essential amino acids”) and can synthesize the remaining 11 in order to suit their bodies needs. However, cats and ferrets, have 12 essential amino acids that must be provided in their diets. Meat proteins are considered “complete” proteins as they contain all the essential amino acids along with many of the non-essentials. So for cats and ferrets, this means that the most direct way to get those amino acids into their bodies is to eat other animals, where the proteins provided are complete and provide every amino acid necessary for them to survive. In vegetarian diets for ferrets, all of them are supplemented with synthetic amino acids to make up for the lack of them provided in the food itself. Most high-quality meat-based foods have no need to supplement with synthetic amino acids. Most synthetic vitamins and supplements are manufactured overseas (China) and are inconsistent and subject to contamination issues.
3. While ferrets do secrete trace amounts of amylase, an enzyme necessary to begin the digestion of carbohydrates, ferrets do not secrete enough of it to effectively eat large amounts of plant matter. The levels they secrete are probably perfunctory and serve to help break down any plant matter consumed through the mustelid’s prey. While ferrets do produce amylase, they don’t produce insulin easily and regularly, and if fed large amounts of carbohydrates over time, the cells of the pancreas responsible for insulin secretion become overworked and this is thought to lead to the development of tumors, called insulinomas. These tumors end up oversecreting insulin, creating very low blood sugar levels in the affected ferret, which can be lethal. Insulinoma is a very common issue among ferrets, and diet is believed to be a major reason as to why. Subjecting ferrets’ bodies to a food that constantly causes their pancreases to go into overdrive is exactly what these vegetarian foods do.
4. Because ferrets cannot break down plant matter effectively, much of it passes through relatively unchanged. This is especially hazardous when fed whole pieces of vegetable and fruit, as it can cause intestinal blockages, which require expensive and risky surgery to correct. In a kibble such as these vegetarian diets, while the items are probably ground into a fine meal before extruded into kibble, the risk of blockage is still great if the ferret swallows pieces of kibble whole without chewing well.
5. A ferret’s intestinal tract can become inflamed when continually subjected to products it cannot digest, and this causes the bowel to produce mucus to help move the food along. This can mean even less of the product is absorbed because the mucus will block up the absorption vesicles of the intestines. This creates malnutrition problems as well as irritable bowel, loose stools, etc.
6. Ferrets, because of their carnivorous nature, utilize fat as their primary energy source. A ferret’s diet, then, needs to be high in fat levels in order to adequately provide energy to a happy fuzz. These foods, while provided fats through soybean oil, are still low in true fats and the soybean oil provided is likely ill-absorbed.
7. The whole marketing scheme of the Evolution Diet is based around animal cruelty in the livestock and agriculture trade. As a vegan, I agree that the whole trade is very faulted, and requires significant change in order to repair the damages done to the planet and our own health. Yes, the majority of the pet food industry is contingent upon the waste products from the human food meat industry, which unfortunately includes 4D meats: dead, dying, diseased, and disabled. I agree that these meats unfit for human consumption are not fit for pet consumption either, but that doesn’t change that our pets still must eat meat. I even agree that the cruelty involved in manufacturing kibble is despicable. However, animal cruelty is a human moral. Ferrets, and cats, and dogs, do not have ethics. Their physiology requires their bodies be nourished by other animals, this is the path their evolution has taken them, and as caretakers we MUST respect that. If you as a consumer and pet owner want to provide a nourishing diet to your carnivore while still being conscientious of the livestock and pet food industry, there are still many commercial foods out there that utilize fresh, USDA-inspected, healthy, wholesome meats. If you are still wary, like I am, and want to impose your principles on your pets, then feed a raw diet. With a well-researched homemade frankenprey, prey-model diet, you can provide organic, sustainably-raised meats to your pets.
YOU make the decision on how to feed your ferrets, no one else does. YOU have the ability to respect them as the sentient, beautiful beings that they are. And doing so absolutely means that they need to eat other animals. We cannot force them to evolve any more than they can force us to devolve. By feeding a vegetarian or vegan diet to your carnivorous pet, you are committing animal cruelty in my book.
If you have any questions about diet and nutrition for you ferrets, please do not hesitate to shoot me an email at firstname.lastname@example.org. I am happy to help you find the diet that fits your ideals as well as your ferrets’ physiology!