Ferret Nutrition for Complete Newbies
where to start
ingredient quality
don't panic
Ferret Food FAQ
why feed a mix of foods?
Intermediate Topics
ferretone, oil treats, and vitamin A & D toxicity
why some cat foods are ferret-suitable
the wild polecat's diet
links to other ferret charts

Why Some Cat/Kitten Foods are Ferret Suitable

The following is an opinion. It is written as an argument, and is not unbiased. I also acknowledge that dry pet food is not ideal for ferrets when compared to natural diets. For the sake of this argument, "suitable" means "suitable in terms of dry kibble". And "cat food" means "cat/kitten food".

"Cat/kitten food is not suitable for ferrets"

I've heard this argument repeated time and time again. While I strongly disagree and want to help people understand why I think some cat food is better than most ferret food, I would prefer to not argue with anyone directly.

Instead I've decided to write out my thoughts here to provide a resource for the counterargument. Hopefully I'll at least be able to help some people think a bit deeper about the topic, and give them more information to use make their own decision. I'll be arguing:

"Some kinds of high quality cat/kitten food are highly suitable for ferrets"

Myth: ferret foods are made differently than cat foods, taking the ferret's shorter digestive tract into account

Almost all dry ferret foods, cat foods, and dog foods are all made through a process called extrusion. If you have $50,000 to spare, you can buy your own machinery here.

The TL;DR-ish version of the process is:
  1. Meats and meat meals (ie. chicken meal, turkey, salmon) are blended together with vegetables (ie rice, wheat, corn, potatoes), vitamins, and minerals to make a dough
  2. The dough is cooked at high heat and pressure and extruded into tiny kibble pieces
  3. These pieces are dried out and sprayed with fats/oils/flavoring/more vitamins
Ferret foods use the same type of machinery and process as cat foods. They don't have any secret extra steps that improve digestability. Given similar ingredients they shouldn't be digested any faster or differently by ferrets than cat foods are.

Things that are likely to improve a food's digestibility for ferrets:
  • limiting the quantity of plant-based ingredients, especially complex carbohydrates
  • having high protein and fat which comes from animal-based ingredients
  • having lots of higher quality muscle meats rather than by-products

    A "cat food" that follows this criteria is going to be better digested than a "ferret food" that doesn't. Or the same as a "ferret food" that does. Poop size is good evidence for this.

    Myth: ferret foods use different ingredients than cat foods

    You can obviously tell just by reading a couple of labels that this isn't true; most cat and ferret foods use the same staple ingredients like chicken/turkey/eggs/fish and potato/rice/peas for the bulk of their food.
    The really low-end ones use things like poultry/poultry by-products/animal fat and corn/corn gluten meal/wheat/brewers rice instead.

    I wanted to show a couple of high-profile ferret foods as examples of just how similar cat and ferret foods can be. My first choice is Zupreem Grain-Free Ferret Diet which is quite possibly based off of Taste of the Wild Rocky Mountain Feline Formula.

    Ingredientschicken mealchicken meal
    sweet potatoespeas
    peassweet potatoes
    chicken fatchicken fat
    pea protein
    potato proteinpotato protein
    natural chicken flavornatural flavor
    fish mealocean fish meal

    As another example, Innova EVO (which some consider to be one of the best brands) puts the EXACT same food into their ferret food bags as their cat food bags. The formulas aren't similar; they're 100% identical. I have e-mailed the company and asked just to be sure. They're honest about it.


    Myth: ferret foods are precisely balanced for ferrets. Cat foods are made for cats so they don't have the right vitamin/mineral balance.

    This is the biggest can of worms I have to open. Sorry, this answer is going to be long.

    The TL;DR is that we don't know a lot of technical detail about ferrets' nutritional needs. Sure we know from their relatives/teeth/digestive tract that they ought to be eating meat, but we don't know precise little details like how much vitamin D, manganese, or sodium they need. We don't even have proof that they need taurine. No one publishes research on ferret nutrition, so we have no way of knowing exactly how a ferret's ideal dietary balance differs from a cat's.

    A correspondence from AAFCO (this speaks for itself):

    Hello, Your message to AAFCO was referred to me for a response since I serve as the chair of the AAFCO Pet Food Committee. You have asked about the nutritional requirements for ferrets.

    You are correct in that AAFCO has approved the nutritional standards for dog food and cat food. AAFCO has established the AAFCO Dog Food (and Cat Food) Nutrient Profiles which is a listing of the recognized nutrients and their levels that must be in dog food and cat food. AAFCO does not determine the essentiality of the nutrients, as the AAFCO Dog Food (and Cat Food) Nutrient Profiles are based on the nutrient recommendations of the National Research Council (NRC) for dogs and cats. The NRC publishes several publications for different species of domesticated animals, but I am unaware of any NRC publication or nutrient recommendation for ferrets. The NRC does issue a Publication Number 10 for the Nutrient Requirements of Laboratory Animals for the Rat, Mouse, Gerbil, Guinea Pig, Hamster, Vole and Fish.

    AAFCO defines "pets" to be dogs and cats, whereas "specialty pets" are defined as those pets that are normally maintained in a cage or tank. If a manufacturer were to claim that their specialty pet food was "complete and balanced", most state regulations require some recognized standard such as the NRC to support the claim. In developing their nutrient recommendations, the NRC does not perform the research studies, but they review the published research studies conducted by private groups, companies and universities. Most research requires funding, so there is obviously more studies performed for livestock to maximize the economic benefit of raising these animals. There are NRC publications for animals such as beef cattle, dairy cattle, goats, horses, and rabbits. There are no NRC nutritional standards for pet birds (other than poultry), for fish (other than species raised for aquaculture), or for any small animal species such as ferrets other than for laboratory animals noted above. I did an Internet search for the nutritional requirements for ferrets, and I saw a hit for the USDA recommendations for ferrets raised in research settings. I could find very little to no information about ferret nutrition at this site.

    Companies selling specialty pet food should not claim that their products are "complete and balanced" unless there is a published AAFCO or NRC nutritional standard for that species of animal. Companies are probably formulating the nutrients in their products based on their own or others' personal observations since there is no scientifically published standard to base their claim of "complete and balanced." We as control officials try to prevent complete and balanced claims that cannot be supported, but such claims can be difficult to control. Some states focus primarily on livestock feed and pet food, and some states even exempt pet food and specialty pet food from regulation.

    Several years ago, several nutritionists met to develop a nutritional standard for the maintenance of pet birds. This group notified AAFCO of their intention, and we were supportive of their endeavor as claims for complete and balanced bird foods were all over the market. After a couple of years, this group abandoned their project because they just couldn't agree. We still have no published and accepted nutritional standard for pet birds.

    So, you are also correct in that you may not be able to trust that a ferret food is complete and balanced. You could ask the company what nutritional standard they use to formulate their products. I can only recommend that you do your own research as to what you should be feeding your ferret, and try to feed your pet a variety of foods to ensure that he is getting the nutrients that he needs.

    By the way, I think your message is a great one, and I applaud you for questioning the claims made for ferret food.

    Teresa Crenshaw
    Chair, AAFCO Pet Food Committee

    Just in case that was too long or too technical to follow, I drew out the processes that are used to decide how to make properly balanced foods for cats and ferrets.

    *very rarely, companies will use a "feeding trial" instead to prove that their food is balanced.
    Here's a link to AAFCO's Nutrient Profile for Cats

    I'm not saying that companies don't spend time or research developing their ferret foods. I'm just saying that the science behind balancing ferret foods is a bit shaky, so I find claims that ferret foods are better balanced than cat foods pretty outrageous.

    Truth: SOME cat foods are NOT suitable for ferrets

    There are a lot of low end cat foods out there. Grocery or department store brands are not appropriate for ferrets. In fact, I would go as far as saying that at least 90% of cat foods are not appropriate for ferrets. But that's no reason to dismiss the 10% that are.

    Myth: People aren't smart enough to learn the difference between good cat food and bad cat food. We should just tell them that cat food is unsafe for ferrets.

    I've noticed a trend with many of those who say that cat foods shouldn't be fed to ferrets. They seem to think that if people are told that cat food is okay for ferrets, they're going to run out to the nearest grocery store and buy some sort of super-low-end cat chow for their ferrets.

    While it's true that there are plenty of cat foods out there that aren't suitable for ferrets, I think we should give people more respect than that. If you're going to try to educate people, please take the time to do it properly. That way you can save them from both bad cat foods and bad ferret foods. Which brings me to my next point...

    Truth: Some FERRET foods are NOT suitable for ferrets

    This is the main reason why I advocate feeding cat foods. There are so many terrible ferret foods out there. Some have 3 of the first 4 ingredients listed as vegetables. Some have no animal protein sources aside from by-products. Some have chunks of fruits or veggies mixed in that could cause a blockage in a ferret's digestive tract.

    You shouldn't assume that a food's going to be properly formulated for ferrets just because there's a ferret picture on the bag. You need to read the label and find out what it's made of before you can decide that.

    Truth: Good ferret foods are usually harder to find than good cat foods.

    The facts are simple. There are more cat owners out there than ferret owners, and the market reflects this. At the time I'm writing this, Petsmart's website lists 11 ferret foods and 173 cat foods.

    Most stores have a very limited variety of ferret foods, and that makes finding good ones very hard. With the ridiculously large variety of cat foods out there on the other hand, there are plenty of options that are great for ferrets.

    For some people, the only options available in their location are:
    a)feed a cat food
    b)feed a very, very low-end ferret food
    In that situation I definitely don't want them to go with a terrible food just because they heard somewhere that cat foods are bad for ferrets.