Category: ferrets

Viral and bacterial infections in ferrets

Ferrets are prone to a number of viral and bacterial infections. There are vaccines available to prevent some of these, but good management practices go a long way to lower the risks of infectious disease in ferrets.

Ferrets are not susceptible to the viruses that commonly produce upper respiratory disease in domestic cats (rhinotracheitis, calicivirus), nor are they susceptible to canine hepatitis. There is also no definitive evidence that ferrets are susceptible to canine parvovirus or feline leukemia virus; therefore, vaccination against these diseases is probably unnecessary.

The most commonly seen viral disease in ferrets include canine distemper and influenza; rabies, epizootic catarrhal enteritis and Aleutian disease are occasionally seen.

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, poor appetite, sneezing, nasal discharge, etc). In general, influenza causes only mild disease in ferrets. Unlike distemper, however, influenza usually passes within 5 days of the onset of illness and ferrets recover. Bacterial infections may complicate the viral infection. If you are suffering from a cold or flu, it is advisable not to handle your ferret until you are well again.

A few cases of lymphoma and lymphosarcoma (cancer) have occurred in ferrets over the years. Some of these cases 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 such an infection. Some researchers believe that leukemia and related diseases among ferrets may be caused by a virus or viruses specific to ferrets.

Bacterial infections aren’t as common as viral infections in ferrets, however a number of 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.

Bacterial pneumonia, proliferative colitis (proliferative bowel disease) and helicobacter gastritis have also been seen in ferrets.

Bacterial pneumonia usually occurs secondary to another disease, such as viral pneumonia. Signs of infection can include nasal discharge, difficulty breathing, increased respiratory rate, loss of appetite, lethargy, discolouration of the mucous membranes, and fever.

Proliferative colitis and helicobacter gastritis causes diarrhoea which leads to severe weight loss. These are often referred to as “wasting diseases” because of the rapid weight loss seen. They occur in ferrets of any age, but most commonly affect young kits up to 20 weeks of age.

Judicious use of antibiotics is usually sufficient for treatment of most, but not all, of these conditions.

Parasitic diseases in ferrets

Most of the external parasites of domestic dogs and cats (fleas, mange, ear mites, etc.) can cause disease in ferrets. However, less is known about the ferret’s susceptibility to the more common internal parasites (roundworms, etc.) of dogs and cats.

Ferrets can suffer from both internal and external parasitic diseases.

Although internal parasitic diseases are uncommon, ferrets can suffer from intestinal parasites.

Ferrets are commonly affected by external parasites such as mites, ticks and fleas.

Intestinal protozoan parasites, also shared by dogs and cats, can cause intestinal disease among ferrets. Coccidiosis is the most common intestinal parasitic disease of ferrets.

Infection with worms (helminths) is rare, but roundworms can potentially pass between ferrets, puppies and kittens. Cryptosporidiosis, a parasitic disease caused by Cryptosporidium, is also occasionally seen in young ferrets, and can potentially pass between ferrets, puppies and kittens. Other protozoan diseases are possible, but rarely seen.

Most ferrets with intestinal parasites won’t show any signs of being infected. However, the following signs may be seen: diarrhoea (with or without blood), weight loss, dehydration, decreased activity, dull hair coat, straining to defaecate, prolapse of the ferret’s rectum, and even death.

Periodic faecal examinations should be performed by your vet to check for such parasites.

Most intestinal parasites can be treated with antiparasitic drugs. Hospitalization may be required in severe cases, but most can be treated with a spot on treatment which is easy to give and stress-free for your ferret.

External parasites are common in ferrets.

Ferrets housed indoors rarely have a problem with fleas or ticks. Fleas and ticks are more common in ferrets that spend time outdoors or who come into contact with infected dogs or cats. Mange and ear mites are common in both ferrets that are housed indoors and those that live outdoors.

Fleas can cause itchiness in your ferret which will result in red patches of skin, scabs and hair loss. Severe infestations can cause blood loss and weakness. Infestations need to be treated vigorously; the ferret, its home environment, and all infested household pets must be treated with an appropriate anti-flea treatment.

Ticks are rarely a problem, but if you do find a tick on your ferret make sure you wear gloves when removing them to avoid exposure to their disease-carrying saliva.

Mange, also known as scabies, is caused by microscopic Sarcoptes scabiei mites. These will cause your ferret to scratch resulting in red patches of skin, scabs and hair loss. Mange also affects the foot pads, known as foot rot, where the feet become red, swollen and sore. Your vet will probably need to do a skin scrape to determine the cause of the itching as the mites cannot be seen with the naked eye.

Ear mites will cause your ferret to scratch its ears or rub its head on the floor in an attempt to scratch its ears. Your ferret may have a dark, waxy discharge from the ear, and in severe cases, your ferret may develop an infection which will require antibiotics.

Most external parasites can be treated with antiparasitic drugs. Most can be treated with a spot on treatment which is easy to give and stress-free for your ferret. However, if your ferret is suffering with ear mites, a more aggressive treatment regime may be necessary which will involve an ointment which will need to be placed directly into your ferret’s ears.

Miscellaneous health problems in ferrets

Two medical conditions of ferrets that demand special mentions are the ferret’s extreme susceptibility to canine distemper and the unusual consequences of female ferrets coming into heat. These are therefore covered in separate factsheets.

However, there are other medical conditions that affect ferrets that are briefly covered here.

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 32°C/90°F, and if water is restricted or not available to ferrets, heat exhaustion is likely and death quite possible. Providing ample shade and spraying your ferret on hot days will help reduce the likelihood of this problem.

Ferrets can also suffer from either kidneys or urinary bladder stones, which can 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, lack of energy and poor appetite.

Surgery is usually necessary to correct this problem, though a special diet may eliminate certain types of stones or prevent recurrence.

Cardiomyopathy is a condition of the heart muscle seen in dogs and cats, which ferrets can also suffer from. Most affected ferrets are males over 3 years of age. The cause for this condition is 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 poor appetite, fatigue, increased periods of sleep, intolerance to exercise, fainting and shortness of breath.

Cardiomyopathy is diagnosed using chest x-rays, an electrocardiogram (ECG), and echocardiography (EKG). All ferrets older than 3 years should have an EKG to screen for this disease.

Ferrets are prone to ringworm, which is a fungal disease of the skin, similar to Athlete’s foot in humans. It 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 with ferrets, with one exception: flea collars should never be used on ferrets.

Canine distemper in ferrets

Ferrets are highly susceptible to canine distemper – a disease normally seen in dogs that is transmitted through moisture droplets. Dogs usually pick it up when sniffing where infected dogs have been, and since the incubation period can be as long as three weeks, it is usually too late to vaccinate once any outbreak has begun.

The initial signs of the disease appear 7-10 days after exposure to the virus and include a lack of interest in food 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, and the pads on the feet become greatly thickened.

Prevention of this disease should be an absolute priority because treatment is useless. Canine distemper is considered 100% fatal in ferrets, with infected ferrets dying approximately 3 1/2 weeks after initial exposure.

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.

Feeding your ferret

Ferrets have unique feeding requirements. They are carnivores and are unable to obtain nutrients from vegetable matter; the food they eat also passes through their digestive system very quickly. For this reason their diet needs to be high in animal protein, fat and low in fibre. A ferret thrives on a varied diet, so the more varied you can make your ferret’s diet, the better.

There are a few specially designed dry complete ferret foods available and are specifically formulated to provide all the nutrients a ferret needs.

The base of your ferret’s diet should consist of a dry food, this is recommended over semi-moist and canned food alternatives because the soft food can lead to gum and dental disease. Once you have a good dry food you can also offer other food to make their diet more varied.


These can be offered as an occasional treat either cooked or raw.


Ferrets aren’t so keen on fish, but it can still be offered as an occasional treat if your ferrets decided they like it.

Meat and bones

Ferrets love both cooked and raw meat, in particular rabbit, poultry and mice. Raw meat should be given fresh and don’t worry about the bones, ferrets can eat bones and they are a great source of calcium, marrowbone and minerals.

Other treats that can be given, but in very small quantities, and not on a regular basis, include:

  • cooked vegetables
  • non-acidic fruits, e.g. raisins, banana and coconut

Food to avoid completely include:

  • dairy products unless they are lactose-free)
  • salty/sugary/spicy food
  • nuts
  • cat/dog food

Most of these cause tummy upsets, even if fed in relatively small quantities, and so are best avoided.

This really is up to you. You could either leave a bowl of dry food for them all the time, this way they can eat when they are hungry, or you could give them a couple of feeds a day, either way, you will soon learn which method is best for your ferret.

You should also remember that your ferret should always have access to fresh, clean water. This can be offered in either a water bottle or a heavy ceramic dish to avoid spillage.


Ferrets make wonderful pets because of their engaging personalities, playful activity and fastidious nature. They can also be easily trained to use a litter tray because they tend to habitually urinate and defaecate in the same places.

Ferrets are extremely intelligent, naturally inquisitive and generally have an affinity for people, and the older a ferret is, the more mellow it is likely to become.

To ensure you interact better and bond with your ferret, it is important that you understand your ferret’s behaviour. The following are some of the most common ferret traits.

This is seen in response to fear, and if so is usually accompanied by hissing and/or their hair standing on end; if this happens to your ferret, the best thing to do is to leave him be until he calms down. Ferrets also back-up when they go to the toilet, which is usually into the corner of their litter tray or run.

Young ferrets (kits) tend to be nippy, but no more so than a new kitten or puppy, however they tend to nip with a little more enthusiasm! Some kits never nip at all, but those that do usually grow out of it.

Many new owners mistake nipping for viciousness, even though the same behaviour in a new kitten or puppy is accepted, but nipping is normal play behaviour between littermates and is often transferred to their human companions. Because this can be the case, parents should not allow small children to play with kits to avoid any unecessary nipping behaviour.

There have been a number of documented cases of ferret attacks on infants and very small children, some of which 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.

If accompanied by backing-up and/or hissing, a puffy tail probably means that your ferret is frightened and should be left alone to calm down.

On the other hand, if your ferret’s tail becomes puffy while investigating his environment or playing, it will mean he is very excited.

The meaning behind this normally depends on what is happening at the time.

Hissing could mean your ferret is angry or frightened and you should leave him along to calm down, or if playing with other ferrets, hissing can be a means of communication.

Your ferret’s body language will usually give your ferret’s mood away!

Ferrets can often be seen shivering or trembling. This usually occurs when they first wake up and is due to excitement and anticipation.

Ferrets very rarely shiver because they are cold.

Like dogs, this is a sign of excitement, and is usually seen when they are playing.