The domestic ferret has become an increasingly popular pet in the United States and other parts of the world in recent years. The domestic ferret, Mustela putoriusfuro, is a member of the mustelid family that includes otters, minks and skunks. Records indicate that the ferret has been domesticated since approximately 4 B.C. In Europe, it was and in some areas is still used for hunting rabbits and rats.
Ferrets are lively, inquisitive, and comical in their movements. They expend a great deal of energy when they are playing and then sleep deeply for long periods. The life span of the ferret is five to seven years on average in the United States. There have been several cases of ferrets living to be over 10 years of age. Geriatric disease problems usually start at around three years of age.
Many people are concerned about the odor of the ferret. Ferrets do not spray the anal gland contents as their relatives the skunks do and, once they are past the "baby" stage or unless they are very frightened, they do not release this material frequently. Therefore, removing the anal glands is an unnecessary procedure in ferrets and in fact does nothing to remove body odor. Neutering the pet, however, will remove 90% of the body odor satisfactorily. Both male and female ferrets that have been neutered will still have a slight "musky" body odor, but most ferret owners find it inoffensive. Ferrets generally do not need bathing; however owners who wish to do so should bathe their pets no more than once every two weeks with a mild pet shampoo.
Males are normally twice the body size of females. The average male ranges in weight from 1 to 2 kg (2 - 5 pounds) and the females from 0.5 to 1.0 kg (1 - 2.5 pounds). Ferrets reach their adult weight by six months of age. There is a normal 20% to 40% weight fluctuation during the year, especially in intact animals, due to changes in the amount of subcutaneous fat present. As would be expected, weight is put on during the fall and lost in the spring. There is also a hair loss that occurs at these same times. Usually the shedding is gradual, but occasionally it may be quite dramatic with all the undercoat coming to the surface over a 24-hour period. When a ferret has had an area shaved, as in the case of surgery, the hair may regrow very slowly (up to three months for complete regrowth), and the skin may develop a dark blue appearance just prior to the hair returning. The dark blue is caused by the presence of hair just coming out of the follicles. The animal's markings including mask configuration, overall hair length, shade, or texture may change with each shed, and this is normal.
The natural or "wild" coloring of the ferret is the sable, which includes very dark-brown or black guard hair on the extremities, a dark-brown or black mask on the face, lighter brown body guard hair, and a cream-colored undercoat. The albino ferret also occurs naturally and appears as do albinos in other species with a white coat and lack of pigment in the iris. In the United States, there are over 20 other recognized colors of ferrets that have been created. These include various shades of silvers (the brown guard hairs are absent with only the cream undercoat and gray and black guard hairs remaining, pandas (the head and neck is white, and the body may be any shade), black-eyed whites (white body hair as in albinos, but they have pigmented irises), cinnamon (a beige overall coat color), siamese (a medium-brown overall coat color), and others.
Males are called hobs
Females are called jills
Young are called kits
Puberty is reached at about five to nine months of age usually beginning the spring after their birth if they are kept under natural lighting conditions. Fertility may last for three to four years. The females cycle repeatedly from March to August and are stimulated by an increase in the photoperiod. When a female is in estrus, the vulva will increase in size dramatically with a slight mucoid discharge, but no blood should be present.
Ferrets are induced ovulators (like cats), and the vulva will decrease in size one to two weeks after breeding. The males also are only fertile during this time with the testicles increasing in size and the body and urine odor becoming more intense. Both male and female ferrets that are in "season" may have urine staining and matted fur around the thighs or abdomen. This is a normal occurrence due to urine being passed frequently and in small amounts in order to mark their territory. Male and female ferrets may be surgically sterilized at four to six months of age.
Jills may remain in estrus for prolonged periods of time if they are not bred, which may result in hyperestrogenism. This condition can lead to local or generalized alopecia or the even more dangerous situation of toxic depression of the bone marrow.
Coitus in the ferret is rather violent and noisy and, may be shocking to the pet owner. The male ferret drags the female around by the neck and mates with her frequently. The receptive female should be submissive and, although she may cry out, she will not fight back. It is recommended to wait until the female has been in estrus at least 10 days and then place her in the male's cage for a maximum of 48 hours. The gestation period is 38 to 44 days (false pregnancies which should last the same amount of time). The litter size is 2 to 17 with eight being the average. The kits are born hairless, blind, and deaf and develop a white hair coat in about two days. In one week, the dark fur comes in, and by two to three weeks it is possible to tell what color they will be as adults. The eyes open between three and four (34 days average) weeks of age, and they can be started on soft food as early as three weeks of age (use the adult food softened with milk or water). Kits can be weaned at five to six weeks of age, but many breeders recommend leaving them together until at least eight weeks of age to enhance socialization. Females return to estrus shortly after the kits are weaned unless it is late fall, at which point they will not go into estrus until the following spring if housed under natural lighting conditions.
Ferrets can be housed either indoors or outdoors. Rabbit- or cat-sized cages of approximately 24 x 24 x 18 inches high are suitable for up to two ferrets. The sides may be wire with holes no larger than 1.0 x 0.5 inches. The floor may be either 0.25 inch wire mesh or solid metal. Wood is not preferred for flooring as it is difficult to clean and retains odors. Solid plastic floors may lead to foot irritation; however linoleum or no-wax type flooring is acceptable. If ferrets are to be kept outdoors, it is essential that they have an enclosed sheltered sleeping area. This may be filled with fresh hay or straw for insulation. In the winter, it also is important to either heat the water source or change it frequently to prevent dehydration due to inaccessibility of frozen water. In the veterinary hospital, be aware that females and small males may be able to squeeze through the bars of the average metal-barred dog or cat cage. Placing a piece of plexiglass over the bars attached with velcro strips or wiring wire mesh to the cage front will make an adequate modification to keep ferrets from escaping.
An enclosed sleeping area or some type of bedding is necessary for psychological well-being. Towels work well, although the occasional ferret may develop the bad habit of chewing and eating the towel. Usually this is just a kit behavior and ceases to be a problem as they approach maturity. Other sleeping materials can be sleeves and legs of sweat suit material, stocking caps, and cardboard or wood boxes.
Ferrets may be litter box trained relatively easily within the cage. Place a small cat litter box in the corner of the cage that the pet has already selected as the toilet area. Clay kitty litter (nonperfumed), pine shavings, or a variety of pelleted paper or other organic products may be used. On occasion the pet may develop what the author refers to as "kitty litter coat" from clay litter material. Ferrets dearly love to dig, and they may spend a large amount of time in the litter box doing so. This may lead to a dry brittle coat due to the desiccating properties of the kitty litter. It also may lead to chronic upper respiratory disease from constantly inhaling the dust. If this situation occurs, the clay litter should be replaced with a pelleted product. If the pet is allowed to roam over a large area, it may be necessary to place several litter boxes around the house, as they will not always return to the cage to defecate or urinate.
Ferrets are extremely good escape artists, and their small size and tubular body shape allows them to pass through very small openings. The owner needs to "ferret proof " the exercise areas by getting on hands and knees and inspecting under cabinets and along baseboards to make sure there are no potential areas to escape. Ferrets are also supreme little thieves, and it is necessary to keep clothing, shoes, and small items such as keys out of their reach, or the owner may never see them again!
It is important to select appropriate toys for ferrets. These little animals have a great love of rubber and unfortunately will tear off pieces of it and swallow it, resulting In gastrointestinal foreign-body obstructions. Do not give ferrets soft latex rubber cat or dog toys with which to play. Keep foam rubber such as shoes (insoles), stereo speakers and head phones, and pipe insulation out of their reach. Ferrets also will burrow into furniture and mattresses and ingest foam rubber stuffing, so it is advisable to cover the bottom of chairs, couches, and beds with hardware cloth or wood. On more than one occasion, ferrets have met with untimely deaths by being crushed in recliner chairs where they were hiding, and it is recommended to remove such chairs from the play area. Suitable toys include small stuffed animals, ping pong balls, golf balls, hard nylon toys, and metal balls. Ferrets dearly love running through pipes and tubes, so providing large mailing tubes and sections of PVC pipe can be an added treat.
Ferrets are carnivorous and have a very short intestinal tract compared to dogs and cats. They have a digestive transit time of three to four hours with a very simple gut flora. They also have no cecum or ileocolic valve. They need to eat frequently, so it is best to offer food free choice. Cannabalism may increase if jills are left too long without food. Pregnancy toxemia also may result if a ferret near term is withheld food for even 24 hours. Starvation with possible fatty liver degeneration may occur inadvertently if ferrets being fed a dry diet are denied access to water (i.e. frozen water source, plugged sipper tube, overturned water bowl, etc.).
Mature pet ferrets have a 30% minimum protein requirement in their diet. This must be in the form of high-quality meat protein with highly digestible amino acids because they digest plant proteins poorly. If the diet has a large amount of plant protein, particularly corn, the ferret may be at risk of developing urolithiasis because of an increase in urine pH. Young growing animals (up to six months) and pregnant and lactating jills should receive closer to 40% high-quality protein in their diet. Weaned kits receiving less than 30% dietary protein were observed to develop abnormally.
Ferrets appear to have a high fat requirement, and the diet should contain at least 20% to 30% fat. Ferrets frequently develop dry brittle coats when deprived of sufficient fat in the diet. Commercially available fatty acid supplements as used in cats and dogs (up to 2 cc/ferret per day) may be utilized to treat poor coat quality. Results should be noted in two to three weeks.
In Europe, Australia, and New Zealand, ferrets are fed primarily a raw or cooked meat diet including both organ and muscle parts, with variations including the addition of dairy products, egg, meat fat, and other supplements. In these areas, ferrets seem to thrive on these diets. In the United States, the current recommendation is to feed a high-quality dry cat food or one of the specially prepared pelleted ferret foods. Check the label to determine that the protein source is primarily high-quality animal and not plant. Ferrets generally prefer poultry and beef flavors over fish. The food should be offered free choice. It may be difficult to convert a ferret from a lower quality diet to a higher quality diet once it is accustomed to it.
Ferrets should be vaccinated for two viral diseases: canine distemper and rabies. Kits should be vaccinated for distemper at six weeks of age and then receive a booster at eight , twelve and fifteen weeks. Rabies vaccine should be given at twelve weeks. These should be given once yearly throughout your ferrets life. Contrary to belief, ferrets are not susceptible to feline leukemia or feline distemper (panleukopenia).
Common Disorders or Conditions:
Ferrets are prone to several disorders such as ear mites, heart failure, heartworms, dental problems and stress related gastric ulceration.
Gentle restraint is generally all that is needed to handle a ferret patient. Kits may be more fractious and may require firmer handling, but the average adult ferret in the United States is a very docile creature. As with any species, increased familiarity with its normal behavior will ease anxiety about handling. It should not be necessary to use gloves. You should keep a spray or squeeze bottle of alcohol or other bitter tasting nontoxic substance (such as bitter apple or orange which are commercially available) at hand to apply to the ferret's mouth in case of the rare bite. These substances will induce the pet to let go. In cases of a very "nippy" animal, it is useful for the owner and/or the practitioner to spray a bitter tasting substance on the hands prior to picking the animal up to minimize problems until the behavior is corrected with frequent handling. You should not put unfamiliar ferrets up to his face, because with the pet's poor eyesight ferrets may view the human nose as an exciting new toy!
A method of restraining a particularly active ferret is called "scruffing." This works in most ferrets to calm them down, although the occasional animal (particularly very young females) may resist and another restraint method may be necessary. The technique is simple. The handler grasps as much skin as possible over the back of the ferret's neck (starting between the ears) and allows the lower feet to hang suspended. Gently stroking the abdomen will aid in relaxing the pet. In this position, the ferret may have its ears cleaned, nails clipped, head examined, abdomen palpated, chest auscultated, and be given subcutaneous or intramuscular injections. Using treats such as a hairball laxative or other sweet or fatty substances are useful as a distraction during unpleasant procedures such as nail clipping and injections.
A helpful method of holding ferrets to restrain their rather active little bodies for examination involves tucking the body under the handlers arm and along the handlers side with the back of the ferret's head held in the palm of the hand. This is a good position in which to give oral medications and to examine the head. Holding the ferret with one hand around the neck and the other firmly in front of the hind legs around the lower abdomen is a useful restraint used for giving injections to a fractious animal.
We hope you will find this information useful and that you have many years of enjoyment with your new pet. Please check the numerous literature sources available for more detailed information on ferrets and their care.
David E. Hammett, DVM
G. Scott Russell, DVM
and the staff of All Creatures Veterinary Clinic, PC
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