HOW TO CHOOSE THE RIGHT FOOD FOR YOUR FERRET

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by Erika Matulich, Ph.D.

Volume 1, Number 5

September / October 1998

 

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You should not rely on the veterinary advice or information provided on this site for diagnosis or treatment of any specific situation. Always consult your own veterinarian for specific advice concerning the medical condition or treatment of your own pet or animal.

Introduction

Ferrets have unique nutritional needs, so it is important that your ferrets eat a dry food that best matches their special requirements. Often, owners feed their ferrets kitten foods, but these foods were not designed with ferrets specifically in mind. Some foods labeled for ferrets are merely modified kitten or mink chows. The best foods are those designed from "the ground up" with the ferret in mind. However, just because a food says "ferret" does not necessarily mean it fills the needs of your ferrets. Reading labels and selecting the right ferret food can make the difference in health, lifespan, looks, and behavior. Ferrets have a quick (3 hour) digestive turnaround, so foods must have easily digestible, nutritious, high-quality ingredients to make sure the nutrients are absorbed in this short time period, and not eliminated.

 

Reading Labels

The purpose of this article is to teach you how to read a nutrition label so you can decide which foods are good for your ferret, and which may be inadequate. We will focus on two parts of the label: the guaranteed analysis and the ingredient listing. The guaranteed analysis lists percentages of protein, fat, and fiber, among other things. Ferrets need certain percentages, which are discussed below.

 

The ingredients list each ingredient in the food, with the highest percentage (by weight) ingredient listed first, second-highest second, and so on. However, the percentages themselves are not listed, so we have incomplete information. For example, two foods could list their top ingredients in the same order: chicken meal, rice flour, and corn meal. But the first food could be chicken meal (45%), rice flour (10%), and corn meal (5%) and the second food could be chicken meal (25%), rice flour (23%), and corn meal (20%). Although the ingredient list was the same, these foods are vastly different. It is unfortunate that manufacturers do not provide us with the percentage information in the ingredient listing. However, the first five ingredients usually make up about 85% of the food content, so we will focus on these ingredients.

 

Protein Requirements

Ferrets need a high protein (32%-38%) diet. Pet foods list these percentages on the label in the guaranteed analysis section; however, just reading the percentages does not tell the whole story. Proteins should come from animal, not vegetable, sources. David Ory with Merrick Pet Foods points out that "ferrets are carnivores, and meat eating animals should eat meat-based, not cereal-based foods." Ferrets have difficulty using or digesting cereal/vegetable proteins for two reasons. First, vegetable proteins do not have a complete amino acid chain required for ferrets. Second, vegetable proteins take 4-6 hours to digest, so most are passed through and not absorbed in the 3-hour timespan of the ferret’s digestive system. Additionally, Judith A. Bell, DVM, warns that regular feeding of plant-source proteins can cause painful uroliths (bladder stones).Foods low in meat proteins can also cause coat problems, bone problems, and gastrointestinal diseases.

 

The primary protein source for a ferret (and the first ingredient on the label) should be meat (usually chicken or poultry). Secondary sources of protein, such as meat meal, whole eggs, liver meal, bone meal, or fish meal, should be in the top five ingredients. Some ferret nutritionists design foods with fish proteins, citing the success of mink chows and desirable proteins and fatty acids from fish. Other ferret nutritionists argue that ferrets do not naturally eat fish, and that fish-based foods are less tasty to ferrets. Beef products may be difficult for a ferret to digest, but research is uncertain on this topic. Lamb is a good ingredient, especially for ferrets with allergies to poultry. There are several lamb and beef-based foods for these allergic ferrets, but make sure there are no other poultry ingredients. Dr. Inga Marty, DVM, has conducted indicating that poultry sources have the most complete amino acid chain that ferrets can utilize, beef sources are less complete, and fish even less. Dr. Marty suggests, however, that more than one protein source should be used in a ferret food; for example turkey as a primary source and fish as a secondary source.

 

Vegetable proteins such as soybeans or cereal grains (corn, wheat, oats, barley, rye, or rice) should be avoided in large quantities; foods that list any of these as their FIRST ingredient should NOT be fed to a ferret. However, you are likely to see these vegetable-based ingredients in the second through fifth ingredients, because grain flours are necessary for carbohydrates. An exception to this list is corn gluten or corn gluten meal; this is a starch used for binding the food together, and is not a source of protein. The key to analyzing protein is to avoid a long listing of grain flours. For example, the following listing [poultry meal, corn flour, brewer’s rice, chicken fat, corn meal] has too many vegetable protein sources in the first 5 ingredients. In fact, from a total guaranteed percentage of 35% protein, over half could be from vegetable sources, thus leaving only 18% usable protein for the ferret. A better ingredient list would be [chicken, corn meal, poultry fat, bone meal, corn gluten] in which more of the ingredients in the top five are from meat sources.

 

Another potential problem source of protein is dairy products. Most ferrets are lactose intolerant and seem unable to utilize the proteins provided by milk and its byproducts. Avoid ingredients such as milk, whey, casein, or cheese, especially in the top five ingredients. Whey seems to be a common culprit in ferret food allergies.

 

Fat Requirements

Ferrets also need a high fat (18%-22%) diet which allows them to digest the proteins and provides for their energy needs. Fat is a concentrated source of energy and provides vitamins A, D, E, and K. Chicken or poultry fat should be the second or third ingredient in the list. Fish oil and flax oil are good sources of Omega-3 dietary fatty acid, which is good for your ferret (it helps with allergies, itchy skin, arthritis, heart disease, and renal failure). However, fish oil may cause the food to have an undesirable odor or be unpalatable to ferrets. Red meat fats (such as beef tallow) are not desirable and may contribute to renal disease. Vegetable fats (vegetable oil, corn oil, etc.) not be listed in the first five ingredients, but may be desirable later in the ingredient list as a source of fatty acids. Dr. Martin Glinsky, nutritionist for 8 in 1 Pet Products, agrees that fatty acids, especially linoleic acid, is important for optimal ferret skin and coat health. The diet should not be too high in fat, or ferrets will eat less, thus getting less protein, minerals, and vitamins.

 

Carbohydrates

A high-quality, simple carbohydrate should be listed second or third in the ingredient list. This could be in the form of brewers rice or rice flour. Corn and wheat flours or other cereal grains are more complex carbohydrates that are not as easily used by the ferret (they also contain more fiber). Corn, however, is a popular ingredient due to its ready availability and low cost.

Ferrets love the taste of sweet foods, but sweets are usually in the form of complex carbohydrates. Ferrets don’t have significant amounts of intestinal flora to break down complex carbohydrates, so these should be avoided. Furthermore, eating a diet rich in carbohydrates can lead to a reduced intake of necessary proteins and fats, which can lead to disease. Sugars should not appear in the top five ingredients, and ideally should not appear at all. Beet pulp is a common sweetener, and is an acceptable ingredient.

 

Fiber

Ferrets do not have a large intestine (cecum) with which to process fiber, so a low-fiber food is necessary. Fiber levels should be 3% or less, which eliminates many cat foods and almost all dog foods. Additional fiber means that your ferret will absorb less nutrients and eliminate more waste. The best source of fiber in ferret food is meat fiber. Another acceptable source is beet pulp. Beet pulp contains ingredients that inhibit the growth of bad bacteria such as E. coli or salmonella, so it appears to be beneficial to your ferret. Again, the analysis of fiber content does not always tell the whole story: a ferret food with a 3.5% fiber content made up of primarily meat fibers is better than a ferret food with 2.5% fiber from vegetable or grain fibers.

 

Wet or Dry?

Most animal nutritionists agree that canned or "wet" foods should not be fed to ferrets on a regular basis. Wet foods may be appropriate for kits under eight weeks of age, ill ferrets, or elderly ferrets with dental problems. Canned foods have so much water in them that the nutrition levels, when calculated on a dry-matter basis, are not adequate for the ferrets. Also, the moisture fills the ferret up faster, so the ferret does not eat enough to get good nutrition. Finally, canned foods can promote tooth decay, and often have many preservatives. If your ferret is very young or ill and needs a wet food, try softening a dry food with warm water, or grind the dry food in a blender and moisten.

 

Extruded or Pelleted?

According to Dr. Thomas Willard of Performance Foods, makers of Totally Ferret, a good ferret food requires a properly cooked starch to hold the nutrients together until eaten. Properly cooked starches are in "extruded" foods, which has a crunchy texture and interesting shape. Improperly cooked starches result in poorly digested foods. Extruded foods are compressed under high pressure, and may have a higher concentration of nutrients in a single serving because they are so compact. John Ulrich of Kellogg’s (the avian and animal feed company) reports that extruded foods allow the cereal grains to be more digestible. Extruded foods, because they are so hard and crunchy, may also help keep your ferret’s teeth clean.

 

On the other hand, the high cooking temperatures of extruded foods may reduce nutrition levels and break down protein amino acids. Pelleted foods that look like long, slender rabbit food pellets are cooked at a lower temperature to protect nutrients. According to Peter Reid, nutritionist for Marshall Farms Premium Ferret Diet, the dried pellet foods have an immediate breakdown in the ferret’s digestive system, which makes nutrients available quickly. This is important because of the fast pass-through of food through the ferret’s digestive system.

 

Other Ingredients

Taurine is thought to be an important supplement for vision. Taurine is an essential amino acid, along with lysine and methionine. Deficiencies in these important ingredients could cause blindness or heart problems. Plant proteins are very low in taurine, so look for added taurine and meat ingredients.

 

Dr. Milton Burglass of Sheppard & Greene has concerns about the premature mortality rate of American ferrets, and notes that added antioxidants such as vitamin E, vitamin C, and beta-carotene may help to reduce the incidences of cancer. He also notes that increased levels of chromium may be helpful with insulinoma problems.

 

Another good ingredient is Brewer's Yeast, a good vitamin B supplement. Also look for low ash content (less than 7%). A premium ferret food should provide the rest of the necessary vitamins and minerals; space requirements do not allow us to cover them all here.

 

Dyes, Fillers, Preservatives

Dyes are unhealthy additives to a ferret food, and fillers just mean less food, less nutrition, and more waste. Avoid dyes and fillers. Many pet foods use preservatives such as BHT, BHA, and ethoxyquin (to keep fats from becoming rancid). Some people feel that these ingredients are carcinogens. Others argue that without them, fats go rancid, and rancid fats are also carcinogens. At this time, there are no definitive research studies that show the effects of these preservatives on the health of ferrets. However, your may feel more comfortable avoiding these artificial preservatives in favor of natural preservatives such as Vitamin E and ascorbic acid (Vitamin C).

 

Shape/Texture

Smaller, textured shapes (such as kitten-sized stars or crosses) seem to be preferred by cats. Ferret testers also seem to prefer these shapes, and the shapes are less likely to get lodged in the roof of the mouth. However, ferrets often bite the ends off these shapes and leave the middle as crumbs. Triangles, circles, or cylinders may also be good. Pellets may not provide as much texture, but could be easier to eat for the ferret.

 

Packaging

Heat, light, and moisture are all damaging to ferret foods. Regular plastic bags are not the best packaging because they let in light, and tiny pinholes let in air, which results in rancid food. Better packaging would be a special sealed plastic laminate, or a double-lined bag, with plastic on the inside and light-blocking paper on the outside, or a carton.

 

Testing

The food you feed your ferret should have been tested and proven on ferrets. You may also wish to look for AAFCO (Association of American Feed Control Officials) certification on foods. The AAFCO is a nonprofit association of federal and state officials that develops guidelines for production, labeling, and sale of animal feed. AAFCO requires either meeting minimum nutrient standards or a 6-month feeding trial. Not all foods will meet AAFCO guidelines.

 

Lifestage Considerations

Breeding ferrets, nursing jills, and kits require higher protein and fat contents than the percentages listed above, which are most applicable to nonbreeding adult ferrets. According to Susan Brown, DVM, kits under six months, breeding animals, and lactating jills have a minimum protein requirement of 35%. Ill ferrets (such as those with insulinoma or recovering from ECE) also have higher nutritional needs.

 

Older or senior ferrets can become overweight if their activity level decreases. Foods with slightly less protein and 16-18% fat may be better. Most important, if your ferret is overweight, do not switch to a cat adult-stage food, a higher-fiber "lite" food, or lower fat food with inadequate protein levels in an effort to keep your senior ferret's weight down. These foods will deny your ferret needed nutrition. Instead, increase activity levels, or switch to a food specifically designed for senior ferrets (Totally Ferret for Older Ferrets and Sheppard & Greene Maxi-Life are formulas specifically designed for senior or overweight ferrets). Do not put your ferret on a diet by withholding food. Because of the high metabolism of ferrets, they need to eat frequently (every few hours throughout the day and night).

 

Palatability

No matter how healthy the food, if it does not taste good to the ferrets, they will not eat it. Unfortunately, many of the unhealthier foods are more palatable to ferrets. Some contain high amounts of sugars. Others (typically grocery-store cat foods) are commonly coated with animal fat or sprayed with phosphoric acid to make them more tasty. This makes your job of switching from a poor-quality but tasty food to a high-quality, less palatable food more difficult.

 

Switching Foods

Whenever you wish to change your ferret's diet, it is important to switch slowly. Mix the old and the new food, and gradually increase the proportion of new food so that after a few weeks, there is only new food. In extreme cases for very finicky eaters, you may have to liquefy the new food and feed through an oral syringe until the new food is accepted. In some cases this procedure is necessary when a ferret only wishes to eat a food that is literally killing the ferret (such as dog food). Another extreme measure is to completely change foods, and wait the ferret out. It may take a few days for a stubborn ferret to accept a new food.

 

Food Amounts

Food should be made available at all times, or "free fed." Do NOT follow instructions on labels (typically for kittens or cats) that indicate once or twice daily feeding of a controlled amount. Again, the fast digestive process of the ferret requires a new meal every few hours, 24-hours per day.

 

Food Cost

The protein quality of commercial foods drives its price, because protein is the highest-cost ingredient, and high-quality proteins (such as those from muscle meat) cost much more than low-quality proteins (grains, feathers, or indigestible tissues). In the case of ferret food, "you get what you pay for." Ferrets must eat much more of a low-quality food than a premium brand to meet their nutritional requirements. A high-quality, concentrated food costs more per pound to buy, but not much more to feed, because the ferret has to eat less. Additionally, potentially expensive health problems can be avoided if a higher-quality diet is fed, so the bottom-line savings may be substantial.

 

Supplements and Treats

With a good, nutritious, well-balanced food, supplements and treats are not necessary for your ferret's health. However, ferrets enjoy the occasional treat, drop of oil, or reward. Fatty acid supplements with linoleic acid (such as Linatone or Ferretone) are healthy if given in moderate quantities. Treats should be given sparingly, and all treats should avoid refined sugars, dairy products, or chocolate products. If you are feeding commercially prepared ferret treats, read the ingredient list with the same guidelines you use for evaluating food. Avoid filling up your ferret with grain products, sugars, and fiber (which make up many ferret treats), because then your ferret won’t get the nutrition from the regular food. Treats high in sugars may be a foundation for insulinoma. Remember that while it may seem healthy to give your ferret fruits (bananas, grapes, pears, melons) or vegetables (peas, mushrooms, squash), ferrets cannot utilize much of the nutrition and the fiber fills them up so they are less likely to eat their meat-based ferret food. In addition, raw onions and raw potatoes can be toxic in large enough quantities. Raw carrots can cause intestinal blockages.

 

Water

The best food is useless unless fed with adequate water. A ferret needs a constant supply of fresh water (changed daily). Ferrets must have water in their gut to digest food and absorb nutrients. Water also helps flush out impurities that can lead to health problems. Ferrets drink more from water dishes than water bottles, so a heavy crock is ideal. On the other hand, water bottles may be more sanitary for an active ferret.

 

Conclusion

You now have the tools to evaluate what to feed your ferret. You now know how to read nutrition labels and compare alternative foods. Remember to have a minimum of 32% protein and 18% fat, but a maximum of about 3% fiber. Make sure the first ingredient is some kind of meat, and the other ingredients do not have too many grain products. Avoid artificial colors and preservatives. When you go out to evaluate foods, you will find that dog food of any kind should not be fed to ferrets. Grocery-store cat and kitten foods usually have poor nutrition and are loaded with dyes and fillers. Even some foods specifically labeled for ferrets are poor quality. You will typically eliminate foods due to their extremely high corn contents (multiple corn ingredients such as ground corn, corn meal, and corn flour) or high fiber levels. Others will not have appropriate sources or levels of protein and fat. Remember that new ferret foods are coming out on the market all the time, such as Kellogg’s Daily Diet Ferret, so check them out! Also keep in mind that nutrition studies and new information can change the current thinking about what is "right" for your ferret, so keep up with these changes.