Ferret Facts
 |  |
The ferret (Mustela putorius furo) is a domestic pet. It is not a wild animal, though ferrets are
descendants of the European polecat (weasel) and are, therefore, close relatives of skunks, mink, otters
and badgers.
Types and Terms
There are several varieties of ferrets, based on coloration. Fitch ferrets (the most popular) are buff-
colored, with black masks, feet and tails. Albino ferrets are white, with pink eyes. There is also the
Siamese ferret. The female ferret is called a “jill,” while the male is called a “hob.” Babies are “kits.”
Physiology
The gestation period of ferrets is 42-44 days (average, 42 days). The average litter size is 8 (range, 2-
17). Kits are born deaf, with their eyes closed. Their eyes open and they begin to hear between 3-5
weeks of age. Their deciduous (“temporary”) teeth begin to erupt at 2 weeks of age, at which time they
begin to eat solid food. Kits generally are weaned onto commercial kitten chow at 4-8 weeks of age.
Kits reach their adult weight at 4 months of age. Males are typically twice the size of females, but both
sexes undergo periodic weight fluctuations. It is not uncommon for the average ferret to add 30-40% of
its body weight in fat deposited beneath the skin in the fall, and lose this fat the following spring. The
average lifespan of ferrets is 9-10 years.
Behavior
Ferrets make wonderful pets because of their engaging personalities, playful activity and fastidious
nature. They can be easily trained to use a litter box because they tend to habitually urinate and
defecate in the same places. Provide a low-sided litter box for easy entry and exit. More than one litter
box may be necessary if the ferret has free run of the house.
There is no innate animosity between ferrets and dogs and cats, and all can usually share a household
with little difficulty. However, ferrets have been known to attack pet birds, so it is advisable for owners
of both to take appropriate precautions to prevent these encounters.
Ferrets are naturally inquisitive and can squeeze through very small spaces. It is important to “ferret-
proof” your house before bringing your pet home. Thoroughly check every room it will inhabit, sealing all
holes and openings wider than 1 inch in diameter. Make sure that all windows that may be opened have
secure screens. Check the openings around plumbing, heating and air conditioning ducts or pipes.
Some kits are small enough to squeeze under some doors. Ferrets are so small and silent that you will
usually not hear them approach. They are easily stepped on when they are sleeping under a throw rug
or suddenly turn up underfoot. Their love of tunneling and their inherent curiosity frequently place them
in potentially dangerous situations. They could very easily crawl unnoticed into your refrigerator, into the
bottom broiler of a stove, through the rungs of a balcony railing, out the front door, or even end up in the
washing machine with the clothes under which the ferret was sleeping. Other dangers include folding
sofa beds and reclining chairs. The obvious solution to avoiding accident and injury is to learn your ferret’
s habits and be constantly vigilant.
To help protect your ferret, especially if it is allowed free run of the house, obtain an adjustable, light-
weight cat collar, the kind with elastic on one end, a small bell, and an ID tag. The bell will signal that
your ferret is underfoot or has perhaps slipped out the front door. The bell also helps to warn caged
birds the pet ferret is nearby. Unfortunately, we have seen a number of cases of serious injury and
death to pet birds caused by ferrets. The collar also indicates to unknowing neighbors (many people
have no idea what a ferret is) that whatever it is, it must be someone’s pet.
While ferrets are not destructive to most household items (furniture, clothing, etc.), some have a
tendency to chew on soft rubber. This is especially dangerous because the pieces of tennis shoes,
Barbie Doll toes, or other rubber items can become impacted in your ferret’s intestines. Ingested pieces
of kitchen gloves or sponges with household chemicals can also threaten your ferret’s life if eaten. Latex
rubber squeak toys should not be given to ferrets because they may swallow parts of them, causing
intestinal obstruction.
All ferrets have an affinity for people. Some enjoy people more than others. The older a ferret is, the
more mellow it is likely to become. Young kits tend to be nippy, but no more than a new kitten or puppy.
They just nip with more enthusiasm. Some kits never nip at all, but most that do eventually outgrow it.
Ferrets have tough skin and kits have sharp little teeth. The roughhousing a kit may do with its
littermates may not be appropriate for its owner’s finger. Many new ferret owners mistake this nippiness
for viciousness, even though the same behavior in a new kitten or puppy is accepted.
There are a number of documented cases of ferret attacks on infants and small children. Some involved
serious injury to the child. Parents must either forbid encounters between pet ferrets and their infants or
very young children, or closely supervise all of these encounters. It is important to point out, however,
that these unfortunate encounters are far less common than those involving household dogs and cats.
Ferrets are unusual animals, but not “exotic.” They have been domesticated for thousands of years and
can be treated under the same set of disciplinary rules you would use for any other domesticated
animal. Ferrets are extremely intelligent and can quickly be taught what they may and may not do.
Diet
The dietary requirements of ferrets can easily be satisfied by feeding commercial cat food. The growth
formulas for brand name cat foods, composed of high-quality meat (not plant) protein are preferred. Dry
kibble is recommended over semi-moist and canned foods because soft foods lead to disease of the
gums and tooth roots.
Table food can also be offered but should be limited to cooked meat, fish and poultry. Fruits and
vegetables may be offered in very limited quantities. Do not feed milk and foods rich in sugars (cookies,
candy) and carbohydrates (pasta, rice, cereals, bread) because ferrets have a great difficulty digesting
these foods. Bones and foods containing bones should not be offered because they are likely to injure
the ferret’s digestive tract.
It is not necessary to offer vitamins or vitamin-mineral supplements to your ferret as long as it is fed as
outlined above. Your veterinarian may recommend these dietary supplements, however, under special
circumstances or for aged ferrets.
Fresh, clean water should be available at all times. Water bottles or heavy ceramic (crock) dishes can be
used for this purpose.
Housing
Ferrets must be confined within the home and when their activities cannot be adequately supervised.
Most ferrets prefer to sleep within a relatively small, enclosed area. A cat- or rabbit-sized wire cage or a
suitably sized dog/cat airline carrier works very well. Wood shavings or a few towels can be used on the
bottom of the enclosure. Ferrets are especially fond of tunneling under towels and prefer to sleep in this
manner.
Odor Control
The objectionable odor of pet ferrets is primarily the result of the influence of sex hormones on normal
skin secretions. Consequently, castrating male and spaying female ferrets is usually done at 6-8 months
of age. Castrating male ferrets also helps reduce any aggressive tendencies. A very pungent and
equally objectionable secretion occasionally is produced by the ferret’s scent (anal) glands. Some
owners also have their pet ferrets descented.
Restraint
When awake, ferrets generally exhibit constant activity. They can be easily picked up, however, and
gently restrained by using both hands to support their weight and provide security from falling and
injury. Ferrets can also be easily restrained for examination, laboratory sample collection, and treatment
by gently suspending them off their feet by the nape of the neck. The relaxation that results from this
method is similar to that exhibited by very young mammals as they are carried in their mother’s mouth
from one place to another.
Disease
Two medical conditions of ferrets demand special mention: the ferret’s extreme susceptibility to canine
distemper and the unusual consequences of female ferrets coming into heat. Other medical conditions
are also briefly discussed below.
Canine Distemper: Ferrets are highly susceptible to canine distemper. The initial signs of the disease
appear 7-10 days after exposure to the virus and include inappetence and a thick mucus and pus-laden
discharge from the eyes and nostrils. A rash commonly appears under the chin and in the groin area 10-
12 days following exposure. The foot pads become greatly thickened. This disease is considered 100%
fatal, with infected ferrets dying 3-3 ½ weeks after initial exposure.
Prevention of this disease should be an absolute priority because treatment is useless. Kits should first
be vaccinated against canine distemper at 6-8 weeks of age (4-6 weeks of age if kits are from
unvaccinated mothers). A booster vaccination is essential 2-3 weeks later. Yearly boosters are
recommended thereafter.
(Note: Please discuss with your veterinarian whether or not your ferret should be vaccinated. Ferrets have a
high incidence of vaccine reaction, and in many cases vaccines would not be recommended)
Heat Periods: Female ferrets are seasonally polyestrus, which means they can come into heat more than
once during the breeding season (March through August). They are also induced ovulators, which means
ovulation occurs after copulation. The onset of heat is recognized by swelling of the external genitialia.
If a ferret in heat does not engage in copulation, she will remain in heat for up to 160 days. If she is
bred, the swelling of the external genitalia usually regress to normal within 2-3 weeks after copulation.
Sustained sexual heat is dangerous and life-threatening because it usually results in bone marrow
suppression. This results in severe anemia and decreases in the number of circulating white blood cells.
Because of this likelihood, any female ferret not intended for breeding should be sterilized (spayed or
ovariohysterectomized) at 6-8 months of age. Female ferrets in heat can be taken out of heat within
about 3 weeks by injection of a specific hormone after the first 10 days of heat. Once out of heat, they
can be spayed before they come back into heat (usually 40-50 days after administration of the hormone).
Rabies: Ferrets are highly susceptible to rabies and can transmit the virus. A rabies vaccine is now
available for use in ferrets. Ferrets 3months of age or older should be vaccinated, with annual boosters
thereafter. Owners of vaccinated ferrets should know, however, that under certain circumstances, public
health authorities may require euthanasia (humane killing) of vaccinated ferrets that have bitten a
person.
All pet ferrets need not be routinely vaccinated for rabies. Chances are remote that a pet ferret living in
an urban household would be exposed to rabies virus through the saliva of a rabid animal. This is
because ferrets, unlike many urban cats, are never allowed to roam freely outdoors, where they may
come into contact with wild animals or other domestic animals.
It is important to understand, however, that pet ferrets not vaccinated against rabies may be
quarantined and even euthanized after a biting incident so as to determine whether the animal was
carrying the rabies virus. On the other hand, vaccinated ferrets are usually not quarantined after biting
incidents. Consequently, each ferret owner must decide whether or not to vaccinate their ferret against
rabies.
Other Viral Diseases: Ferrets are not susceptible to viruses that commonly produce upper respiratory
disease in domestic cats (rhinotracheitis, calicivirus), nor are they susceptible to canine hepatitis. There
is no definitive evidence that ferrets are susceptible to canine parvovirus or feline leukemia virus;
therefore, vaccination against these diseases is probably unnecessary. A few cases of lymphoma and
lymphosarcoma (cancer) have occurred in ferrets. Some of these ferrets tested positive for feline
leukemia virus, while others tested negative. Though a cause-and-effect relationship cannot be proven
by such a small number of cases, the possibility exists that ferrets may become infected with feline
leukemia virus. Cancer can be one possible result of an infection. Some researchers believe that
leukemia and related diseases among ferrets may be caused by a virus or viruses specific to ferrets.
Feline Infectious Peritonitis: This is another serious viral disease of cats for which ferret susceptibility is
not yet known. There is no vaccine available for this disease in ferrets. Because of the lack of
knowledge regarding ferret susceptibility and the other feline diseases previously discussed, ferret
owners should be extremely cautious with regard to their pet’s exposure to cats, especially those
exhibiting signs of illness and those of unknown health status.
Influenza: It is interesting to note that ferrets are susceptible to infection with several strains of human
influenza (“flu”) virus. Signs of this illness may mimic those of canine distemper (listlessness, fever,
inappetence, sneezing, nasal discharge, etc.). Unlike distemper, however, influenza usually passes
within 5 days of the onset of illness, and ferrets recover. Treatment with a specific anti-influenza-A drug
may be recommended. Such treatment is not recommended if bacterial infection complicates the
influenza infection.
Parasitism: Most of the external parasites of domestic dogs and cats (fleas, mange mites, ear mites,
etc.) can cause disease in ferrets. Less is known about the ferret’s susceptibility to the more common
internal parasites (roundworms, etc.) of dogs and cats. Protozoan (one-celled) parasites, also shared by
dogs and cats (especially Giardia and Coccidia), can cause intestinal disease among ferrets. Periodic
fecal (stool) examinations should be performed by your veterinarian to check for such parasites.
Appropriate treatment can then be given, if warranted.
Ringworm: Ringworm (a fungal disease of the skin similar to athlete’s foot) has been reported in young
ferrets and may be transmitted by infected cats. As a rule of thumb, products manufactured and
intended for use in and on cats (dewormers, flea products, ringworm medications, etc.) are safe and
suitable for use in and on ferrets, with one exception: flea collars should never be used on ferrets.
Heartworm Disease: Ferrets are susceptible to heartworm disease, a mosquito-transmitted illness seen
mostly in dogs. Ferret owners must carefully consider the pros and cons of preventive therapy for this
disease. Some ferrets may have adverse reactions to the drug used for heartworm prevention. Further,
the average ferret is very unlikely to be bitten by an infected mosquito unless it lives in an area of heavy
heartworm infection and is often exposed (housed outdoors) to mosquitoes. Most ferrets housed
exclusively indoors are unlikely to become infected by heartworms and should not require preventive
therapy.
Bacterial Infections: Various bacteria can produce a variety of diseases in ferrets, including botulism,
tuberculosis, dysentery (caused by Campylobacter fetus), and abscesses and infections caused by bite
wounds and other injuries. Judicious use of antibiotics is usually sufficient for treatment of most, but not
all, of these conditions.
Heat Stroke: Ferrets lack sweat glands and are somewhat compromised in their ability to maintain
normal body temperature in extremely warm environmental temperatures. If the temperature rises
above 90 degrees F, and if water is restricted or not available to ferrets, heat prostration is likely and
death quite possible. Providing ample shade and spraying your ferret on hot days will help reduce the
likelihood of this problem.
Urinary Stones: Urinary stones, either within the kidneys or urinary bladder, may cause serious problems
in ferrets. Both sexes seem to be affected equally. Signs of urinary stones include blood in the urine,
inability to urinate, a swollen and painful abdomen, vomiting, listlessness and inappetence. Surgery is
usually necessary to correct this problem, though a special diet may eliminate certain types of stones or
prevent recurrence.
Cardiomyopathy: Cardiomyopathy is a condition of the heart muscle seen in dogs, cats and ferrets. Most
affected ferrets are males over 3 years of age.
The causes for this condition are unknown. The muscle walls of the heart become thickened, reducing
the ability of the heart to pump adequate quantities of blood to the rest of the body. Signs include
inappetence, fatigue, increased periods of sleep, intolerance of exercise, fainting and shortness of breath.
Cardiomyopathy is diagnosed using chest x-rays, an electrocardiogram (EKG), and echocardiography (a
diagnostic technique using ultrasound waves). All ferrets older than 3 years old should have an EKG to
screen for this disease.
Miscellaneous Problems: Insulin-secreting tumors are not rare among ferrets. These tumors cause
persistently low blood sugar levels, which produce weakness, depression, fainting spells, changes in
behavior and convulsions.
A number of autoimmune diseases of ferrets have been identified. These types of diseases arise when
the ferret’s immune system begins to destroy one or more of the body’s components. These diseases
are usually very serious. Signs may include depression, lethargy and weakness. Veterinarians
experienced in working with companion exotic animals should be consulted if this type of disease is
suspected. An evaluation of the blood (and perhaps other tissues) is necessary to diagnose autoimmune
disease.
Cataracts are fairly common in pet ferrets (young and old). Their significance and genetic predisposition
are not fully understood.
Ferrets’ nails (claws) can become extremely sharp and should be trimmed periodically. The method used
and guidelines followed are identical to those used in trimming the nails of a dog or a cat. Ferrets should
not be declawed.
For More Information
Below is information on other organizations that can provide more tips on ferret health and care:
The American Ferret Association
PMB 255
626-C Admiral Drive
Annapolis, MD 21401
www.ferrets.org
Phone: 1-888-FERRET-1
afa@ferret.org
In the Company of Ferrets, Inc.
Director: Laura Palmer
Director: Liz Tveite
Stillwater & Elk River, MN
651-439-5209
Or 763-441-8542
www.ferretasylum.com
luvfuzzies@aol.com
Ferret Central
www.ferretcentral.org
International Ferret Association
P.O. Box 522
Roanoke, VA 24003
descendants of the European polecat (weasel) and are, therefore, close relatives of skunks, mink, otters
and badgers.
Types and Terms
There are several varieties of ferrets, based on coloration. Fitch ferrets (the most popular) are buff-
colored, with black masks, feet and tails. Albino ferrets are white, with pink eyes. There is also the
Siamese ferret. The female ferret is called a “jill,” while the male is called a “hob.” Babies are “kits.”
Physiology
The gestation period of ferrets is 42-44 days (average, 42 days). The average litter size is 8 (range, 2-
17). Kits are born deaf, with their eyes closed. Their eyes open and they begin to hear between 3-5
weeks of age. Their deciduous (“temporary”) teeth begin to erupt at 2 weeks of age, at which time they
begin to eat solid food. Kits generally are weaned onto commercial kitten chow at 4-8 weeks of age.
Kits reach their adult weight at 4 months of age. Males are typically twice the size of females, but both
sexes undergo periodic weight fluctuations. It is not uncommon for the average ferret to add 30-40% of
its body weight in fat deposited beneath the skin in the fall, and lose this fat the following spring. The
average lifespan of ferrets is 9-10 years.
Behavior
Ferrets make wonderful pets because of their engaging personalities, playful activity and fastidious
nature. They can be easily trained to use a litter box because they tend to habitually urinate and
defecate in the same places. Provide a low-sided litter box for easy entry and exit. More than one litter
box may be necessary if the ferret has free run of the house.
There is no innate animosity between ferrets and dogs and cats, and all can usually share a household
with little difficulty. However, ferrets have been known to attack pet birds, so it is advisable for owners
of both to take appropriate precautions to prevent these encounters.
Ferrets are naturally inquisitive and can squeeze through very small spaces. It is important to “ferret-
proof” your house before bringing your pet home. Thoroughly check every room it will inhabit, sealing all
holes and openings wider than 1 inch in diameter. Make sure that all windows that may be opened have
secure screens. Check the openings around plumbing, heating and air conditioning ducts or pipes.
Some kits are small enough to squeeze under some doors. Ferrets are so small and silent that you will
usually not hear them approach. They are easily stepped on when they are sleeping under a throw rug
or suddenly turn up underfoot. Their love of tunneling and their inherent curiosity frequently place them
in potentially dangerous situations. They could very easily crawl unnoticed into your refrigerator, into the
bottom broiler of a stove, through the rungs of a balcony railing, out the front door, or even end up in the
washing machine with the clothes under which the ferret was sleeping. Other dangers include folding
sofa beds and reclining chairs. The obvious solution to avoiding accident and injury is to learn your ferret’
s habits and be constantly vigilant.
To help protect your ferret, especially if it is allowed free run of the house, obtain an adjustable, light-
weight cat collar, the kind with elastic on one end, a small bell, and an ID tag. The bell will signal that
your ferret is underfoot or has perhaps slipped out the front door. The bell also helps to warn caged
birds the pet ferret is nearby. Unfortunately, we have seen a number of cases of serious injury and
death to pet birds caused by ferrets. The collar also indicates to unknowing neighbors (many people
have no idea what a ferret is) that whatever it is, it must be someone’s pet.
While ferrets are not destructive to most household items (furniture, clothing, etc.), some have a
tendency to chew on soft rubber. This is especially dangerous because the pieces of tennis shoes,
Barbie Doll toes, or other rubber items can become impacted in your ferret’s intestines. Ingested pieces
of kitchen gloves or sponges with household chemicals can also threaten your ferret’s life if eaten. Latex
rubber squeak toys should not be given to ferrets because they may swallow parts of them, causing
intestinal obstruction.
All ferrets have an affinity for people. Some enjoy people more than others. The older a ferret is, the
more mellow it is likely to become. Young kits tend to be nippy, but no more than a new kitten or puppy.
They just nip with more enthusiasm. Some kits never nip at all, but most that do eventually outgrow it.
Ferrets have tough skin and kits have sharp little teeth. The roughhousing a kit may do with its
littermates may not be appropriate for its owner’s finger. Many new ferret owners mistake this nippiness
for viciousness, even though the same behavior in a new kitten or puppy is accepted.
There are a number of documented cases of ferret attacks on infants and small children. Some involved
serious injury to the child. Parents must either forbid encounters between pet ferrets and their infants or
very young children, or closely supervise all of these encounters. It is important to point out, however,
that these unfortunate encounters are far less common than those involving household dogs and cats.
Ferrets are unusual animals, but not “exotic.” They have been domesticated for thousands of years and
can be treated under the same set of disciplinary rules you would use for any other domesticated
animal. Ferrets are extremely intelligent and can quickly be taught what they may and may not do.
Diet
The dietary requirements of ferrets can easily be satisfied by feeding commercial cat food. The growth
formulas for brand name cat foods, composed of high-quality meat (not plant) protein are preferred. Dry
kibble is recommended over semi-moist and canned foods because soft foods lead to disease of the
gums and tooth roots.
Table food can also be offered but should be limited to cooked meat, fish and poultry. Fruits and
vegetables may be offered in very limited quantities. Do not feed milk and foods rich in sugars (cookies,
candy) and carbohydrates (pasta, rice, cereals, bread) because ferrets have a great difficulty digesting
these foods. Bones and foods containing bones should not be offered because they are likely to injure
the ferret’s digestive tract.
It is not necessary to offer vitamins or vitamin-mineral supplements to your ferret as long as it is fed as
outlined above. Your veterinarian may recommend these dietary supplements, however, under special
circumstances or for aged ferrets.
Fresh, clean water should be available at all times. Water bottles or heavy ceramic (crock) dishes can be
used for this purpose.
Housing
Ferrets must be confined within the home and when their activities cannot be adequately supervised.
Most ferrets prefer to sleep within a relatively small, enclosed area. A cat- or rabbit-sized wire cage or a
suitably sized dog/cat airline carrier works very well. Wood shavings or a few towels can be used on the
bottom of the enclosure. Ferrets are especially fond of tunneling under towels and prefer to sleep in this
manner.
Odor Control
The objectionable odor of pet ferrets is primarily the result of the influence of sex hormones on normal
skin secretions. Consequently, castrating male and spaying female ferrets is usually done at 6-8 months
of age. Castrating male ferrets also helps reduce any aggressive tendencies. A very pungent and
equally objectionable secretion occasionally is produced by the ferret’s scent (anal) glands. Some
owners also have their pet ferrets descented.
Restraint
When awake, ferrets generally exhibit constant activity. They can be easily picked up, however, and
gently restrained by using both hands to support their weight and provide security from falling and
injury. Ferrets can also be easily restrained for examination, laboratory sample collection, and treatment
by gently suspending them off their feet by the nape of the neck. The relaxation that results from this
method is similar to that exhibited by very young mammals as they are carried in their mother’s mouth
from one place to another.
Disease
Two medical conditions of ferrets demand special mention: the ferret’s extreme susceptibility to canine
distemper and the unusual consequences of female ferrets coming into heat. Other medical conditions
are also briefly discussed below.
Canine Distemper: Ferrets are highly susceptible to canine distemper. The initial signs of the disease
appear 7-10 days after exposure to the virus and include inappetence and a thick mucus and pus-laden
discharge from the eyes and nostrils. A rash commonly appears under the chin and in the groin area 10-
12 days following exposure. The foot pads become greatly thickened. This disease is considered 100%
fatal, with infected ferrets dying 3-3 ½ weeks after initial exposure.
Prevention of this disease should be an absolute priority because treatment is useless. Kits should first
be vaccinated against canine distemper at 6-8 weeks of age (4-6 weeks of age if kits are from
unvaccinated mothers). A booster vaccination is essential 2-3 weeks later. Yearly boosters are
recommended thereafter.
(Note: Please discuss with your veterinarian whether or not your ferret should be vaccinated. Ferrets have a
high incidence of vaccine reaction, and in many cases vaccines would not be recommended)
Heat Periods: Female ferrets are seasonally polyestrus, which means they can come into heat more than
once during the breeding season (March through August). They are also induced ovulators, which means
ovulation occurs after copulation. The onset of heat is recognized by swelling of the external genitialia.
If a ferret in heat does not engage in copulation, she will remain in heat for up to 160 days. If she is
bred, the swelling of the external genitalia usually regress to normal within 2-3 weeks after copulation.
Sustained sexual heat is dangerous and life-threatening because it usually results in bone marrow
suppression. This results in severe anemia and decreases in the number of circulating white blood cells.
Because of this likelihood, any female ferret not intended for breeding should be sterilized (spayed or
ovariohysterectomized) at 6-8 months of age. Female ferrets in heat can be taken out of heat within
about 3 weeks by injection of a specific hormone after the first 10 days of heat. Once out of heat, they
can be spayed before they come back into heat (usually 40-50 days after administration of the hormone).
Rabies: Ferrets are highly susceptible to rabies and can transmit the virus. A rabies vaccine is now
available for use in ferrets. Ferrets 3months of age or older should be vaccinated, with annual boosters
thereafter. Owners of vaccinated ferrets should know, however, that under certain circumstances, public
health authorities may require euthanasia (humane killing) of vaccinated ferrets that have bitten a
person.
All pet ferrets need not be routinely vaccinated for rabies. Chances are remote that a pet ferret living in
an urban household would be exposed to rabies virus through the saliva of a rabid animal. This is
because ferrets, unlike many urban cats, are never allowed to roam freely outdoors, where they may
come into contact with wild animals or other domestic animals.
It is important to understand, however, that pet ferrets not vaccinated against rabies may be
quarantined and even euthanized after a biting incident so as to determine whether the animal was
carrying the rabies virus. On the other hand, vaccinated ferrets are usually not quarantined after biting
incidents. Consequently, each ferret owner must decide whether or not to vaccinate their ferret against
rabies.
Other Viral Diseases: Ferrets are not susceptible to viruses that commonly produce upper respiratory
disease in domestic cats (rhinotracheitis, calicivirus), nor are they susceptible to canine hepatitis. There
is no definitive evidence that ferrets are susceptible to canine parvovirus or feline leukemia virus;
therefore, vaccination against these diseases is probably unnecessary. A few cases of lymphoma and
lymphosarcoma (cancer) have occurred in ferrets. Some of these ferrets tested positive for feline
leukemia virus, while others tested negative. Though a cause-and-effect relationship cannot be proven
by such a small number of cases, the possibility exists that ferrets may become infected with feline
leukemia virus. Cancer can be one possible result of an infection. Some researchers believe that
leukemia and related diseases among ferrets may be caused by a virus or viruses specific to ferrets.
Feline Infectious Peritonitis: This is another serious viral disease of cats for which ferret susceptibility is
not yet known. There is no vaccine available for this disease in ferrets. Because of the lack of
knowledge regarding ferret susceptibility and the other feline diseases previously discussed, ferret
owners should be extremely cautious with regard to their pet’s exposure to cats, especially those
exhibiting signs of illness and those of unknown health status.
Influenza: It is interesting to note that ferrets are susceptible to infection with several strains of human
influenza (“flu”) virus. Signs of this illness may mimic those of canine distemper (listlessness, fever,
inappetence, sneezing, nasal discharge, etc.). Unlike distemper, however, influenza usually passes
within 5 days of the onset of illness, and ferrets recover. Treatment with a specific anti-influenza-A drug
may be recommended. Such treatment is not recommended if bacterial infection complicates the
influenza infection.
Parasitism: Most of the external parasites of domestic dogs and cats (fleas, mange mites, ear mites,
etc.) can cause disease in ferrets. Less is known about the ferret’s susceptibility to the more common
internal parasites (roundworms, etc.) of dogs and cats. Protozoan (one-celled) parasites, also shared by
dogs and cats (especially Giardia and Coccidia), can cause intestinal disease among ferrets. Periodic
fecal (stool) examinations should be performed by your veterinarian to check for such parasites.
Appropriate treatment can then be given, if warranted.
Ringworm: Ringworm (a fungal disease of the skin similar to athlete’s foot) has been reported in young
ferrets and may be transmitted by infected cats. As a rule of thumb, products manufactured and
intended for use in and on cats (dewormers, flea products, ringworm medications, etc.) are safe and
suitable for use in and on ferrets, with one exception: flea collars should never be used on ferrets.
Heartworm Disease: Ferrets are susceptible to heartworm disease, a mosquito-transmitted illness seen
mostly in dogs. Ferret owners must carefully consider the pros and cons of preventive therapy for this
disease. Some ferrets may have adverse reactions to the drug used for heartworm prevention. Further,
the average ferret is very unlikely to be bitten by an infected mosquito unless it lives in an area of heavy
heartworm infection and is often exposed (housed outdoors) to mosquitoes. Most ferrets housed
exclusively indoors are unlikely to become infected by heartworms and should not require preventive
therapy.
Bacterial Infections: Various bacteria can produce a variety of diseases in ferrets, including botulism,
tuberculosis, dysentery (caused by Campylobacter fetus), and abscesses and infections caused by bite
wounds and other injuries. Judicious use of antibiotics is usually sufficient for treatment of most, but not
all, of these conditions.
Heat Stroke: Ferrets lack sweat glands and are somewhat compromised in their ability to maintain
normal body temperature in extremely warm environmental temperatures. If the temperature rises
above 90 degrees F, and if water is restricted or not available to ferrets, heat prostration is likely and
death quite possible. Providing ample shade and spraying your ferret on hot days will help reduce the
likelihood of this problem.
Urinary Stones: Urinary stones, either within the kidneys or urinary bladder, may cause serious problems
in ferrets. Both sexes seem to be affected equally. Signs of urinary stones include blood in the urine,
inability to urinate, a swollen and painful abdomen, vomiting, listlessness and inappetence. Surgery is
usually necessary to correct this problem, though a special diet may eliminate certain types of stones or
prevent recurrence.
Cardiomyopathy: Cardiomyopathy is a condition of the heart muscle seen in dogs, cats and ferrets. Most
affected ferrets are males over 3 years of age.
The causes for this condition are unknown. The muscle walls of the heart become thickened, reducing
the ability of the heart to pump adequate quantities of blood to the rest of the body. Signs include
inappetence, fatigue, increased periods of sleep, intolerance of exercise, fainting and shortness of breath.
Cardiomyopathy is diagnosed using chest x-rays, an electrocardiogram (EKG), and echocardiography (a
diagnostic technique using ultrasound waves). All ferrets older than 3 years old should have an EKG to
screen for this disease.
Miscellaneous Problems: Insulin-secreting tumors are not rare among ferrets. These tumors cause
persistently low blood sugar levels, which produce weakness, depression, fainting spells, changes in
behavior and convulsions.
A number of autoimmune diseases of ferrets have been identified. These types of diseases arise when
the ferret’s immune system begins to destroy one or more of the body’s components. These diseases
are usually very serious. Signs may include depression, lethargy and weakness. Veterinarians
experienced in working with companion exotic animals should be consulted if this type of disease is
suspected. An evaluation of the blood (and perhaps other tissues) is necessary to diagnose autoimmune
disease.
Cataracts are fairly common in pet ferrets (young and old). Their significance and genetic predisposition
are not fully understood.
Ferrets’ nails (claws) can become extremely sharp and should be trimmed periodically. The method used
and guidelines followed are identical to those used in trimming the nails of a dog or a cat. Ferrets should
not be declawed.
For More Information
Below is information on other organizations that can provide more tips on ferret health and care:
The American Ferret Association
PMB 255
626-C Admiral Drive
Annapolis, MD 21401
www.ferrets.org
Phone: 1-888-FERRET-1
afa@ferret.org
In the Company of Ferrets, Inc.
Director: Laura Palmer
Director: Liz Tveite
Stillwater & Elk River, MN
651-439-5209
Or 763-441-8542
www.ferretasylum.com
luvfuzzies@aol.com
Ferret Central
www.ferretcentral.org
International Ferret Association
P.O. Box 522
Roanoke, VA 24003