Ferrets are carnivores, and their digestive tract is very streamlined and short compared to humans (omnivores) or even other carnivores, such as dogs and cats. Although your ferret can eat vegetables, fruits and other non-meat items, they do not derive much nutrition from non-meat items. Anything your ferret eats will pass from entry to exit in about 4 hours, so there is not very much time for digestion. Your ferret's digestive system is also not well suited for digesting complex carbohydrates or even large amounts of simple carbohydrates; most of your ferret's dietary calories come from protein and fat. (It has even been suggested that ferrets on a sufficiently rich diet will get all the carbohydrates they need from fat.)
Because of his simple digestive system and his inability to digest many kinds of foods, there are many familiar foods you should not feed your ferret. There are also foods you should not give your ferret in large quantities. Also, never assume that just because your ferret likes eating certain foods, they are good for him. Follow the guidelines below about what not to feed your ferret, and you'll prevent some substantial health problems, including dehydration and intestinal blockage.
- Don't give your ferret large quantities of food, including commercial ferret food, if it's a sudden change in his diet. If your ferret has been getting one brand of food for months, and you suddenly switch to another, your ferret will likely start having diarrhea. That's serious, since rapid dehydration and even death can occur. If you have to switch brands, do it slowly, introducing the new food a little more each day over many days.
- Don't give your ferret any kind of sugar, simple or complex, in large amounts, though very small amounts can be tolerated (see listing for treats below). Ferrets can't digest sugars. Lactose is especially bad, so don't give your ferret dairy products (which contain lactose), including cow's milk and made-from-cow's-milk cheese, cream, butter, chocolate and ice cream.
- Don't give your ferret large amounts of fiber, especially daily. A diet high in fiber, given long enough, can cause your ferret to refuse appropriate food, including commercial ferret food, when you try to switch. Also, large amounts of fiber can cause either diarrhea or a prolapsed rectum.
- Don't give your ferret alcohol of any kind, even ethyl alcohol (which is what people drink). This includes foods that contain alcohol, such as eggnog. Because of your ferret's small size, even a small volume of alcohol can kill him. * Don't give your ferret candy of any kind, especially chocolate. Candy should not be given because of the large quantity of simple sugars in it. Chocolate, besides having too much sugar and cow's milk in it also has theobromine, a substance that is very poisonous to animals. It diminishes the blood flow to the brain and can cause heart attacks and a variety of other life-threatening problems.
- Don't give your ferret nuts or seeds, even if they are broken into pieces. Nuts are indigestible and can easily cause intestinal blockage. Sunflower seeds are the worst of all nuts to let your ferret eat. Don't even let your ferret have popcorn, which have baked and hardened kernels your ferret might ingest.
- Don't give your ferret large amounts of vegetables or fruits. Most vegetables and some fruits are not good for ferrets because of their fiber. Also, fruits have too much sugar. Certain vegetables, such as carrots and celery, should never be given raw, since they are hard enough that even small pieces can block your ferret's intestinal tract.
- Don't give your ferret anything with caffeine in it.
- Don't give your ferret food that's very salty, including delicatessen or processed meats (pepperoni, salami, jerky, cold cuts) or junk food.
Conflicting reports exist on ethoxyquin and BHA as to whether or not either is toxic to ferrets. Likely, the amounts in commercial pet foods are not toxic; studies have shown neither is toxic to cats when used in cat food. Other pet foods (including ferret food) lack ethoxyquin and BHA and use either vitamin C or E as a preservative.