Ferret Care Advice From A Veterinarian Who Is Quite Fond Of Them

Ron Hines DVM PhD

Ferret Health Care Library Link  

Please do not introduce your ferret to your dog without very close supervision! Not all dogs like ferrets – at least not until they get to know each other from a protective distance.

Do Ferrets Make Good Pets?

Over the years many ferrets and I have shared a household. We have always enjoyed each other’s companionship.

Domesticated ferrets have been used to flush rabbits out of their burrows since Roman times. King Richard of England issued a decree in 1384 allowing his clerk to hunt rabbits with his ferrets and shortly thereafter, prohibited hunting with ferrets on Sundays. More recently, their fondness for exploring narrow passageways has found them specialized employment. (see here)

Ferret makes excellent household companions – provided their musky odor does not bother you or your human partner. The personalities of ferrets are quite unlike dogs and cats. So spent plenty of time with a friend’s ferret to see if they appeal to you before buying one. If no friend has one, a ferret interest club will help you locate a cooperative ferret owner. Pay no attention to what the pet store employees say, they are hot to make a sale. I also discourage your purchasing a ferret for a friend or for your child unless they are involved in the decision and your child is mature and responsible enough. Ferrets are inappropriate playmates for young children.

Ferret attributes make it hard to rate their intelligence as compared to a cat or a dog. They make poor watchdogs. They will not alert you that someone is at the door. They rarely come when called. They sleep a lot in the daytime. If ability to learn new behaviors and tricks is high on your list of needs, perhaps ferrets are not for you. They are no Einsteins. Ferrets will always behave like ferrets. Their positive attributes are that they are patient, tolerant and tranquil. They love to burrow and sleep curled up in soft fabric. When wide awake, they love to play and dance about as they softly vocalize. They enjoy exploring nooks and crannies. They are economical to maintain. It has been my observation that ferrets that did not have sufficient human contact when they were still nursing on their mothers rarely became optimal pets. They are the only ones that occasionally bite me during health exams. Ferrets tend to get into accidents when not provided with a safe cage. They are best liberated when their owners are home, owners not distracted and guests and parties not in progress. Party residues and unkempt households are always a threat to ferrets due to their curiosity and fearless uninhibited nature.

The scientific name for a domestic ferret is Mustela putorius furo. Ferrets belong to a family of animals known as Mustela. This group includes weasels, mink, badgers, otters and skunks. Ferrets are strict carnivores (meat eaters). In the wild, they live on mice, bugs, frogs and other small prey. There are three primary types of ferrets, the endangered American black-footed ferret that you might see reintroduced into the western United States or in a zoo, the undomesticated European polecat, from which domesticated ferrets originated and the Russian steppe. Some divide the European species further based on minor coloration differences.

How Did Ferrets Originally Become Popular Pets In The United States?

Ferrets were used extensively in medieval times to hunt rabbits. Unlike American cottontail rabbits, European hares dig burrows or warrens and ferrets were used to flush them out.

Ferrets became popular as pets in the United States in the 1970s chiefly due to the efforts of one man, Mr. George Marshall, of Marshall Research Farms located in Wolcott in western New York State. In 1939, he began raising ferrets in the backyard of their family farm. According to the Marshall family, it was a common practice for adjoining farmers to keep a pet ferret for assistance flushing rabbits out of brush piles or for rodent control when their father, George, was a child. The senior Mr. Marshall was a friend of mine. I first met him in 1966 in Washington DC. At the time, I worked there for the NIH. Mr. Marshall was an entrepreneur. His first inclination was to market these animals to us as research subjects. He was a fixture at every AALAS convention. When that fizzled, he concentrated on introducing ferrets to the pet trade.

What It Takes To Care For A Ferret

Ferrets normally have a wobbly, unstable gait. Some might mistake that for a medical issue. As I mentioned, they are fearless and very curious. Ferrets have short attention spans. Unlike dogs and cats, they seem to rely more on their tactile senses (touch & whiskers) rather than smell and vision as they explore new objects. Their love for exploration and squeezing themselves into tight spaces can lead to dangerous situations such as becoming wedged inside the mechanisms of washing machines, dryers, refrigerators and HVAC systems. When they are awake, they are constantly busy checking out their environment. These periods do not last long however since ferrets sleep up to 18 hours a day.

Ferret Biology:

Traditionally, American pet owners purchase ferrets that have already been descented and neutered. Early age descenting does not appear to have ill health effects. But many people, including myself, do not find the natural scent of ferrets objectionable. Alternatively, I have found that washing them bi-weekly (every 2 wks) in baby or kitten-safe shampoo with a cream rinse will keep this odor to a minimum. Just be sure you do not dry out their coat excessively.

However, early age neutering might be unwise. If you go to this webpage, you will see that early age neutering has many long-term health downsides for dogs and cats. Many of the issues faced by early age neutered dogs and cats are hormonal issues. Early age neutered ferrets also commonly suffer serious hormonal issues later in life. If neutering them a bit later in their life minimizes those issues remains unknown. I would avoid neutering male ferrets of any age. Because non-spayed female ferrets become trapped in dangerous estrus when not mated, leaving them intact after 4 months and not in the presence of an unneutered male is not an option. I suppose a vasectomized cohabitating male might be an option, but I have never attempted that. If you have, let me know.

Un-neutered ferrets reach sexual maturity at 5-8 months. As occurs in all the Mustella family, ferrets are “induced ovulators” that means they must mate in order to release eggs from their ovaries (ovulate). When unspayed female ferrets are not bred they become “stuck” in estrus (heat, = “in season”) with disastrous results. With their estrogen levels remaining unnaturally high, fatal aplastic anemia and immune system suppression is usually the result. (read here)

Ferret pregnancies last a little over one month. Ferrets normally have two litters a year – one in the spring and the other in the fall. Not only female ferrets cycle. Un-neutered male ferrets testicle size and body weight also increases twice a year. Unneutered male and female ferret’s weights can vary as much as 45% depending on the season of the year. Their hair coats also become sparser or thicker depending on their point in the estrus cycle. Spayed and neutered ferrets do not show as pronounced changes. Old-time ferret breeders would pluck a portion of hair from their jills’ (females) back. When the fur began to re-grow, they knew the female was pregnant.

Baby ferrets are born immature and undeveloped with scant body fur and their eyes shut. Their eyes open by the time the babies are one month old. Baby ferrets usually wean themselves between 6 and 8 weeks.

Ferret Colors:

Over the years many color variations have been developed. These include cinnamon, chocolate sable, silver, white with black eyes, panda, Shetland sable, sterling, butterscotch, champagne, blaze, black-eyed white, marked whites and albino. No matter what color you choose, there will still be the same ferret personality inside. My advice is to be cautious about purchasing “rare” colored ferrets. Rarity in the pet trade is usually a synonym for highly inbred. Inbreeding concentrates the DNA of body-wide genetic defects as well as trendy color patterns. (read her) You can read about the dangers of inbreeding when it comes to dogs and cats here.

Ferrets hair coats darken and thicken in the winter – especially if they are exposed to natural lighting and shorter day length. They often “blow” their coats (molt) in the fall and spring in response to the changing natural light cycle (circadian rhythm).

How To Speak Ferret:

Devout ferret lovers delight in using language developed by ferret-assisted hunters (ferreters) in Medieval England. These animals have been around so long that a whole vocabulary of words developed around them.

Jill is not the name of someone’s girlfriend. Unspayed female ferrets are called jills. Spayed female ferrets are called sprites. Not Calvin and Hobs – un-neutered male ferrets are referred to as hobs and neutered males are called gibs. Baby ferrets, like foxes, are called kits. The natural brown coat color of ferrets is called fitch (=sable).

How Long Do Most Ferrets Live?

Well cared for ferrets commonly have a life span of 7-9 years and occasional, very exceptional ferrets, are said to have lived to be 12. (ref) I do not recall encountering a ferret older than 9. Unfortunately, a group of all-too-common endocrine gland diseases end the lives of many ferrets at a relatively young age when compared to the average lifespans of dogs and cats. 

Getting Your Home Ready For A Ferret:

Setting up a ferret-friendly home is quite different from arranging for a new family dog, cat or toddler. It can be a challenge. As I mentioned, ferrets seek out nooks and crannies and love to explore them. Those are the places where, in the wild, they would find eligible prey. The tighter the fit the better they like it. It is best to set up some safe attractive location rather than let your ferret choose its own. Small cardboard boxes, milk crates, flower pots, Christmas stockings, tough dryer vent hose and portions of 4-6 inch PVC pipe make great, safe nooks. Things that unravel, collapse or can be chewed up make bad nooks. Flexible plastic film is a no no. So are impervious bottles and jars in which a ferret might get stuck and asphyxiate. Rubber bands are a no no. So is anything with portions small enough to be torn off and swallowed. You will need to store cleaning supplies, pesticides and medications high and out of their reach. Toilet seats need to be down. Cooking stoves in use never left unattended. Washer and dryer doors never left open – particularly when they contain clothes. The mechanisms of recliners are accident-inviting for ferrets. Accessible Christmas ornaments and tinsel also present a problem come holiday time.

Ferrets are escape artists who will squeeze through the smallest of holes. Once escaped from the house, they cannot retrace their steps. If their head gets through an opening, the rest of them will follow. Every little escape rout must be plugged. Ferrets also have a talent for wedging themselves into the chassis of refrigerators, washers and dryers, all of which can cause them serious injury.

Ferret-size hammocks are available to sleep in but canvas backpacks, empty cartons, old hats and purses work equally well.

What Kind Of Toys Do Ferrets Like?

Ferrets love toys. The best ferret toys are infant-safe toys and paper bags or toys designed specifically for ferrets. Toys designed for pet birds are generally safe as well. Ferrets are notorious for swallowing items that then plug them up! That can be fatal. Do not leave anything loose or available in your home that would be a danger to a toddler. Key ring charms and medallions are often made of pot metal (zinc) with impurities of lead. When swallowed or gnawed on, both can lead to anemia.

Can Ferrets Be House-trained?

Yes. Ferrets can be trained to use a cat litter box. Training works best when the ferret is confined for a week or two to a cage no larger than three or four times the size of his/her litter box with the litter box placed inside. Use a pelleted cellulose litter and not a self-clumping silica clay litter. Silica makes them sneeze.

Can I Keep More Than One Ferret?

Yes, most ferrets get along well with a partner – or even a threesome. They can be the same or different sexes. If you do not have a considerable amount of spare time to spend with your ferret you might consider purchasing a partner so that they can entertain each other. The pair should be approximately the same age.

How Much Space Will My Ferret Need?

Although many believe that pet ferrets can be successfully housed in outdoor cages as well as indoors; I found that ferrets kept outdoors in hutches by my clients generally suffered more health issues and lived shorter lives than those kept indoors as family members. But I cannot say that it was the outdoor living that caused that. People inclined to keep pets out of doors are sometimes the same people who devote less resources and time to their care. In my experience outdoor “yard dogs” and roaming cats also have considerably shorter lives. Nevertheless, I strongly recommend that pet ferrets not be kept in outside cages. Opossums, raccoons and rodent vermin will soon make visits. All carry a variety of disease that can be life-threatening to ferrets.

When ferrets are kept outside they can tolerate temperatures as low as 20F and as high as 85F. At low temperature their food consumption often doubles. Ferrets housed out of doors need to be given monthly heartworm preventative. A reliable water source is essential. Sipper bottles are always safer than crocks – better yet, one of both.

Ferrets do love to go for out-of-doors strolls. This is perfectly fine as long as the ferret is harnessed and on a leash and strange dogs are not present. Keep them away from dog poop, standing water and recently sprayed lawns and foliage. Unleashed ferrets are not good judges of location and quickly wander off and become lost if your cell phone rings, and you become preoccupied.

What Kind Of Cage Should I Get? Do I Even Need A Cage?

Yes, you need a cage as much as a baby needs a playpen. When ferrets are not under your supervision indoors, most owners keep their ferrets in a cage constructed of vinyl-dipped or powder-coated wire. Some call them crates because they find the word cage less acceptable. Do not use galvanized mesh – it is too rough on their tender noses and foot pads and the zinc plating is not healthy when licked. A cage 24 inches by 35 inches by 18 inches high will house two ferrets comfortably if they get ample daily out-of-the crate-time. Larger cages with multiple levels are even better. Ferrets naturally prefer confined spaces, so we theorize that their caging space requirement are not as great as dogs and cats.

Characteristics of Most Happy Ferret Owners:

Ferrets also make good companions for families and individuals’ whose spare time is limited. As I mentioned, in pairs or singly, ferrets, like cats, are good at entertaining themselves. Having a ferret is not an all-consuming activity. They are not “needy” pets as are many dogs, and they are not prone to separation anxiety and self-destructive behaviors. Many believe that the ferret’s contentment in solitude is genetic and due to the polecat’s preference for a solitary existence in the wild. Yet ferrets still require a high degree of your commitment and responsibility for their welfare. If you have a human partner, be sure that commitment to a ferret is mutual. If you anticipate life changes, it’s probably not a good time for a ferret addition. If you are lonely for overt expressions of affection, a dog is probably a better choice. If going to sleep on your lap is sufficient, pick a ferret. If you travel a lot, ferrets do not do well with extended stays at boarding kennels, motels, pet shops or veterinary hospital kennels. They treasure peace and quiet.

If you live in an apartment or high-rise condo and the ordinances permit them, ferrets make good apartment and high-rise pets. They are not noisy, their needs are manageable, they are small and economical. They pose no danger to other residents. Keep the windows closed and locked. Ferrets in good health also make good pets for elderly folks that are inclined toward a ferret’s personality. Ferret owners tend to have traits somewhere between cat owners and dog owners. In fact, many ferret owners also own dogs and cats. Ferret owners also tend to appreciate the comical side of life shown in the topsy-turvy behavior of their pets.

What About Food And Water?

Ferrets need fresh water at all times. They easily overheat and become thirsty. Many owners feed them from glazed food-grade crocks or plastic no-tip containers designed for cats. They are less likely to be flipped over than light weight stainless pans. I like to teach my ferrets to use stainless-steel ball bearing sipper tubes and bottles. When this device is new to my ferret, I rub some cream cheese or ice cream on the end to get them used to licking it. keep the water crock as a back-up for a week or two.

What Sort Of Diet Should I Feed My Ferret?

Ferrets have a short digestive tract, so they can’t eat very much at a time. Several brands of ferret chow are available from pet supply outlets. I prefer diets with approximately 38% protein and 20% animal fat. Chicken and eggs are excellent label ingredients. The ferret’s natural diet contains little fiber and their digestive system is not equipped to deal with much of it. So, I try to keep the fiber content at 3% or less. If quality meat and eggs are the protein source, supplemental taurine in their diet is unnecessary. With the water removed (dry weight) whole mice, a favorite prey of wild polecats are about 60% protein and 24% fat on dry weight basis.

As time goes by, ferrets, like all pets, will become obese when overfed. Ferrets are intermittent snackers, so food should be available at all times. But their daily food consumption needs to be monitored because it is not in their interest to become overweight. An accurate scale to weigh them periodically is always a wise purchase.

I suggest you not purchase your ferret’s food from small pet shops. Their product turnover is rarely sufficient to insure a fresh supply and storage conditions are rarely optimal. These single-owner stores also have a tendency to stock boutique brands whose ingredients and true analysis are less predictable.

That said, I have never seen a ferret that developed a health issue that I attributed to feeding it a high-quality diet intended for feline kittens. Some of the quality kitten brands contain 36%+ high quality animal protein and 23% fat. Avoid brands that include fish and/or have high vegetable or fruit content. Fish ingredients have a tendency to rancidity and the ability to destroy thiamine.

For better dental health, I feed ferrets crunchy dry kibble rather than canned diets. Their kibble can be moistened when the ferrets are less than 11 weeks old. When ferrets are fed moisten, wet or canned diets, their oral health suffers unless their teeth are occasionally brushed with cat-approved toothpaste, or they are given occasional high protein (40%+) low fiber, low sugar ferret or cat dental treats.

Ferrets do not tend to do well when their diets change frequently. I find one good food and keep them on that food as long as I can. Should you have to change diets, make the change gradually. Ferrets will eat and enjoy items that they are really not designed to consume and that are not good for them – items such as candy, pasta, table foods and high fiber or sugary items. The frequent FDA pet food recalls present a problem. Ferrets tend to fixate or imprint on whatever foods they ate as kits. I do not know if that is due to taste, mouth feel or smell. So if your ferret’s particular food becomes unavailable due to a recall, call the company that made it and ask which lot numbers are known to be safe.

What Kinds Of Veterinary & Health Care Will My Ferret Need?

Toenail Trim:

Ferrets need their toenails clipped occasionally. I own every imaginable kind of pet toenail trimmer – but I prefer using a human toenail clippers to do this. The blood vein of a ferret’s nail is quite easy to see. If a toenail should bleed, it can be pressed into a bar of soft Ivory soap to stop the bleeding. Roll your ferret up in a towel and take off only a little flake of the nail material at a time. Have a seasoned ferret owner or veterinary nurse show you the proper technique first.

Hairballs:

Most ferrets shed their coat (molt) twice a year. In some it is more pronounced than in others. Daily exposure to unfiltered natural sunlight (the UV rays) intensifies molt. During molting periods, ferrets are more susceptible to hairballs. Treat them with an over the counter hairball remedy (flavored petrolatum) designed for cats.

Intestinal Obstructions:

Ferrets – particularly younger ones – love to eat spongy and stringy non-food material. These ingestions can easily block their small intestines and lead to a rapidly progressing, life-threatening illness. Ferrets seem to have a particular fondness for ingesting small soft rubber items – like the buttons on TV remotes and calculators. Foam rubber mattress foam and rubber bands are two other favorites. Unfortunately, none of these things are likely to show up on your veterinarian’s ordinary x-rays. Some can be palpated through the pet’s abdomens. In other cases, a dose of oral barium will make these objects more visible on x-rays. Obstructed ferrets become depressed, stop eating and drinking and may show diarrhea. Vomiting abdominal pain and fever are common. High white blood cell counts are as well. A ferret’s normal body temperature is about 103F (39.4C). Anything above or much under that is cause for concern. Ferrets showing these signs should be taken to your veterinarian immediately.

Cancer:

Ferrets in the United States are highly prone to tumors of the adrenal glands, pancreas (insulinoma) and the lymphatic system (lymphomas). There is much controversy as to why. Species genetics, early age neutering inbreeding, diet (too many carbs) and artificial lighting may all be involved. I listed them in what I believe to be the order of their importance. 

These endocrine gland-associated cancers begin to appear in pet ferrets at quite an early age – but only if one compares ferrets to the ages at which similar tumors begin to occur in dogs, cats and humans. That is unfair to do because even under the best of conditions, the entire Mustella family, including ferrets, have much shorter potential lifespans. Within the mustella family, lower species body weight equals higher metabolic rate and a shorter natural life (weasels 4-6 years, mink 10 years, badger 10-14 years). Common shrews are not mustella. But like mustella they are strict carnivores. Shrews probably have the highest metabolic rate of all mammals. (read here) The average life span of a shrew is ~14 months. That your ferret will not live as long as your average cat or average-to-small size dog is something you as a potential ferret owner need to accept.

Canine Distemper:

Ferrets are susceptible to the distemper virus of dogs and to human influenza. They should be vaccinated against distemper with a vaccine that is approved for use in ferrets. (read here) Ferrets usually arrive having had one initial canine distemper vaccination. I give them a second booster distemper vaccination when they are 12-14 weeks of age. Many veterinarians revaccinate ferrets against canine distemper yearly. I have never seen a case of distemper in a ferret that received a single approved canine distemper vaccine product after it was 12 weeks of age. So, I do not recommend yearly revaccination. Over-vaccination can be bad for the health of all pets. (read here) At the most, give them a booster in 3-4 years.

Stress & Diarrhea:

Ferrets are quite susceptible to problems that are related to stress, such as change in their environment, and new diets. These events often cause vomiting and diarrhea. Sometimes the diarrhea is quite severe. Sometimes it is bloody. These little animals can quickly become dehydrated and weak. It is always best to make husbandry changes very gradually – not all at once. Cases of diarrhea and vomiting need to be accessed by your veterinarian. When severe, treatment often includes subcutaneous fluids, a bland easily absorbed diet, systemic injectable antibiotics, body temperature support and perhaps corticosteroids and antacids.

Ear Mites:

Ferrets are susceptible to the same ear mites that infect dogs and cats. Generally, ear mites are not present when ferrets are purchased directly from reputable breeders. But ferrets do pick them up in pet shops and less reputable ferret breeder stock pass them on from mother to offspring. Much less frequently, ferrets pick ear mites up at home from close association with another infected pet. Your veterinarian should carefully examine the ear canals of all new ferrets – even if they appear normal. A ferret’s outer ear canals are normally quite collapsed and harder to visualize than the ear canals of dogs and cats. Scratching, head shaking, and excessive crud in and surrounding the ear canals can be a sign of the presence of ear mites. A drop or two of baby or mineral oil generally asphyxiates ear mites. Ear mite products approve for kitten are also acceptable. I just massage in the oil and let ferret sling out wax and debris while under a bath towel. I repeat that until no more debris are seen, and then I use a Q-tip to gently clean the outer portion of the ear. Do not put anything down into the ear canal. If one ferret in your household is positive for ear mites, treat them all. Read an article specifically on ear mites in ferrets here.

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