Common DiseasesNon-Infectious DiseasesInfectious Diseases

Common diseases in ferrets

Intestinal blockages
Caused by eating something indigestible, such as an eraser, a rubber band, some fabrics, or even a good-sized hair ball (accumulated from grooming), which gets stuck. Symptoms may include (one or more of) lack of bowel movement, constipation, bloating, vomiting or heaving, drooling, and others. Blockages may occur at any point in the digestive tract, from the throat through the lower intestine, even in the stomach where the object may move around and produce only intermittent symptoms. Blockages are serious and occasionally fatal; the most important immediate concern is to keep your ferret hydrated, which you can do by giving him 5 cc of water every 4 hours from a baby feeding syringe. You can try giving your ferret large doses of hair ball remedy every 30 minutes for an hour or two to see if the blockage passes, but if not, take him to a vet right away for an X-ray, barium study, and/or surgery to remove it. Laxatone or a similar hair ball remedy/laxative can help prevent this.
Tumors or lesions of the adrenal glands
Symptoms vary, including hair loss spreading from the base of the tail forward, lethargy, loss of appetite, and loss of coordination in the hindquarters. In females, often the most prominent sign is an enlarged vulva as in heat. Often, however, a tumor will be present without showing any signs at all, so if your ferret is going in for any surgery, the vet should take a look at the adrenal glands as well (if time permits -- ferrets lose body heat very quickly in surgery). The left gland seems to be affected more often than the right.
Islet cell tumors (insulinoma)
These are tumors of insulin secreting cells in the pancreas. Their main effect is a drop in the blood sugar level, and they are also common enough in older ferrets, even without symptoms, that if your pet is having surgery for something else, a quick check is worthwhile. Symptoms include lethargy, loss of appetite, wobbly gait, and pawing at the mouth; in more severe cases attention lapses (staring into space) or seizures may also occur. If you're more than a minute from your vet and your ferret has a low enough blood sugar level to be having seizures, call the vet and ask if you should rub Karo (corn sugar) syrup or honey on your pet's gums to raise it just enough to bring him out of the seizure.
Lymphoma or lymphosarcoma
This is a cancer of the lymphatic system. There are two main types, "classic" and juvenile. Classic lymphoma occurs in older ferrets and causes enlarged lymph nodes and irregularities in the blood cell count, but often the ferret doesn't show any outward signs until the disease has progressed pretty far, at which point the ferret suddenly gets very sick. Conclusive diagnosis is by aspiration or biopsy of a lymph node, and treatment is chemotherapy. Juvenile lymphoma is completely different. It affects ferrets under 14 months, doesn't generally cause enlarged lymph nodes, and hits very hard and fast.
Splenomegaly [enlarged spleen, usually a swelling in the upper abdomen]
In situations where a neoplasm is not present [this is a common symptom of lymphosarcoma], the pros and cons of splenectomy should be discussed with your veterinarian. If an animal simply has a large spleen, but shows no signs of illness or discomfort, it is safer for the animal to leave it in. However, if the animal shows signs of discomfort, such as lethargy and a poor appetite, or a decrease in activity, the spleen should probably be removed. These animals also need good nursing care to get them back on their food. Often caused by H. mustelae infection (see below). With proper care - recovery rates are over 90%.
Helicobacter mustelae infection
A bacterial infection of the stomach lining, Helicobacter mustelae is extremely common in ferrets. Animals with long standing infections (generally older animals), may develop gastric problems due to the bacteria's ability to decrease acid production in the stomach. Signs of a problem include repetitive vomiting, lack of appetite, and signs of gastric ulcers (see above). Helicobacter infection and gastric ulcers often go hand in hand - the relationship between infection and gastric ulcer formation has not been totally worked out, although there is currently a lot of research in this area.
Cutaneous vaccine reactions
Subcutaneous vaccination with rabies or other vaccines may, over a period of weeks, cause a hard lump at the site of vaccination. The lump simply consists of a large area of inflammation and most commonly are seen around the neck. The lumps can be removed, and generally do not cause a major problem for your pet. Similar lesions may be seen in vaccinated dogs and cats.
Urinary tract infections and prostate trouble
Signs include frequent urination, straining to urinate, and possibly odd looking or smelly urine. Unspayed females in heat, and spayed females with swollen vulvas due to adrenal disease , are particularly prone to UTIs. Treatment generally consists of a course of antibiotic (usually Amoxicillin); if the ferret doesn't respond to that, the possibility of bladder stones should be considered.
In males, what looks like a UTI may be (or be aggravated by) an inflamed prostate, also generally caused by adrenal disease. In this case the prostate, which is normally tiny, can be palpated, and a greenish goo can often be expressed from it. Taking care of the adrenal problem should clear up the prostate trouble too.


by Dr. Susan Brown, DVM

GI Foreign Bodies

    This is the most common cause of wasting and acute abdominal disease in the ferret under 1 year of age. It occurs with less frequency in older ferrets.

    Ferrets love to chew and eat rubber and "sweaty" objects. The most common foreign bodies we remove are latex rubber pet toys, foam rubber, insoles and soles of shoes, pipe insulation, chair foot protectors, along with towels, cotton balls, plastic, metal, and wood.

    Hair balls are very common particularly in the ferret 2 years of age and older.

    Most foreign bodies remain in the stomach if they are too large to pass and cause a slow wasting disease that may last for months. (This is the way that most hair balls present.) However, if the foreign material passes out of the stomach and lodges in the small intestine, then the pet becomes acutely ill, severely depressed, dehydrated, in extreme abdominal pain and finally coma and death within 24 to 48 hours if surgery is not performed.

    Other signs that your pet may have a foreign body are pawing at the mouth frequently, vomiting (although remember that many pets with foreign bodies do not vomit), appetite that goes on and off, black tarry stools that come and go.

    Prevention is by use of a cat hair ball laxative either every day or every other day (about 1") and ferret proofing your house on hands and knees for potential foreign body items.

    Treatment is generally surgery, because if it is too large to leave the stomach, it has to come out somehow!

Aplastic Anemia

    • A common cause of death of unspayed breeding females.
    • The cause is a condition caused by high levels of the hormone estrogen that is produced during the heat period which in turn suppresses the production of vital red and white blood cells in the bone marrow. This suppression is irreversible as the disease advances and death occurs from severe anemia, bleeding (because the blood can't clot properly), and secondary bacterial infections because there aren't enough white blood cells to fight.
    • Signs are seen in animals in heat 1 month or longer (they can stay in heat up to 180 days if unbred), and include general depression and hind limb weakness that seems to occur suddenly and sudden loss of appetite. Additionally there may be marked hair loss and baldness on the body.
    • Upon closer exam the gums appear light pink or white, and there may be small hemorrhages under the skin. A complete blood count should be done to determine the severity of the damage to the bone marrow.
    • If the condition is advanced, there is no treatment as it is irreversible, and euthanasia is recommended. If the disease is caught early, treatment may include a spay, multiple transfusions and other supportive care.
    • Prevention is by having animals not designated for breeding spayed by 6 months of age. Those to be used for breeding should use the hormone HCG for taking them out of heat during cycles when they will not be bred. The use of vasectomized males can sometimes be unreliable, and we do not recommend it.

Anal Gland Impaction

    • Caused when the animal has a blockage to the outflow of anal gland secretion or abnormally thick anal gland material.
    • Signs are few, doesn't seem to cause them much pain. If the gland ruptures, a draining hole will be seen near the anus, and the pet may lick at the area frequently.
    • Treatment is by surgical removal of the anal glands. Even if only one is affected now, remove both as the other may become affected later.
    • There is no prevention, and this disease does not occur with sufficient frequency to warrant routine anal gland removal in all ferrets.


    • Caused when the lens of the eye becomes opaque. Light can no longer reach the retina and the animal becomes blind. In ferrets it is primarily seen in animals under one year of age and is considered to be hereditary. In other cases it may be caused by aging of the eye in very old animals or as a result of injury to the eye.
    • Signs are almost nonexistent. Ferrets have very poor eyesight and do not depend on it for much. Many people are surprised to find that their ferrets are blind. They eyes will have a whitish blue cast to the area of the pupil.
    • Treatment is unnecessary.
    • Prevention of hereditary cataracts is by not repeating the breeding.


    • Seen generally in animals over 3 years of age, rare in young. Caused by an abnormal thinning or thickening of the heart muscle which interferes with blood flow through the heart.
    • Signs include a marked decrease in activity, the need to rest in the middle of the play periods, great difficulty in awakening from sleep, and as the disease progresses one may see coughing, difficulty breathing, fluid build-up in the abdomen and a general loss of condition.
    • Diagnosis is by X-ray and EKG.
    • Treatment is dependent on which type of heart muscle abnormality is present. There is no cure for this disease, treatment helps to alleviate symptoms and reduce he work load on the heart and attempt to prolong life.

Urolithiasis (Bladder Stones)

    • The cause is not completely understood. A high ash content of the diet and possible underlying bacterial or viral infections, and even some genetic predisposition may all play a part. This condition is rarely seen in animals on a low ash cat food.
    • Signs include blood in the urine, difficulty in urinating (may be accompanied by crying when urinating), "sandy" material being passed in the urine, and in the most severe cases there may be a complete blockage leading to no urine being passed and eventual depression, coma and death.
    • Treatment depends on the size of the stones. Surgery may be indicated or a change to a special diet may solve the problem.
    • Prevention is by feeding a low ash diet.

Parasitic health problems

by Dr. Susan Brown, DVM

Ear Mites

    • Caused by a small mite that lives in the ear and sucks blood and is picked up from other animals with mites (including dogs and cats).
    • Signs are very minimal to none. Ferrets seem to tolerate mites very well. Occasionally there may be an excessive amount of ear wax produced, extensive scratching of the ears, and small black pigmented areas that appear on the ear.
    • Treatment is with Ivermectin at 1 mg/kg divided into two doses with each dose dropped into each ear. This is repeated in two weeks. All the animals in the house should be treated. Wash bedding the same day as treatment and a bath for the pet wouldn't hurt, either. They also may be treated with Tresaderm daily for 14 days.


    • Caused by an insect that spends a small portion of its life on the animal and lives in the surrounding environment laying eggs the rest of the time.
    • Prevented by spraying or powdering your animals 2 times a week with a pyrethrin product if they go outside. If you already have them, the house must be treated also.

Infectious diseases

by Dr. Susan Brown, DVM

Influenza virus

    • Caused by the same complex of viruses that cause disease in humans. They can catch it from humans or other ferrets.
    • Signs include a runny nose (clear discharge), runny eyes, sneezing, coughing, decrease but not total loss in appetite, lethargy and occasionally diarrhea. In newborns it may be fatal.
    • Treatments is generally nothing specific except rest and loving care. They generally get over it in 3 to 7 days (recall how long your flu lasted, and they will generally be the same), The antihistamine product Chlor Trimeton may be used at 1/4 tablet 2 times daily for sneezing that may interfere with sleeping or eating. If the appetite is totally lost or if any green or yellow discharges appear or if there is extreme lethargy, these animals should be seen by a veterinarian.
    • Prevention is washing hands and no kissing when you are dealing with a cold. Also remember, they can give the flu right back to you!

Canine Distemper

    • A 100% fatal disease that is still very much out there! It is caused by a virus that attacks many organs in the body. The virus can stay alive for a long time on shoes and clothes that have come in contact with infected material. (Such as from walks in parks or other areas where animals roam).
    • Signs range from acute [quick] death to a slow progressive disease which usually starts as an eye infection and progresses to a rash on the chin and lips and abdomen, and thickened hard pads on the feet. Diarrhea, vomiting, severe lethargy are other possible signs. The disease may be very drawn out with seizures and coma at the end.
    • There is no treatment for distemper. Euthanasia is the kindest solution as it is a long and painful way to go.
    • Prevention is by vaccination with the Fromm-D [or Fervac-D] distemper vaccine. Use of [some] other vaccines have occasionally caused cases of distemper in ferrets. The schedule would be the first shot at 6 weeks of age then 8 weeks, 11 weeks, 14 weeks and annually thereafter. The vaccine WILL NOT last for 3 years in the face of an outbreak. Ferrets do not need vaccines containing leptospirosis, hepatitis, parainfluenza or any other dog virus.

Neoplasia (Cancer)

by Dr. Susan Brown, DVM


    • This is a disease of the lymphatic system of the body which is an important part of the immune system. The cause is unknown but investigation is being done to determine if there is a virus involved. It can occur in ferrets of any age.
    • Signs are very variable, and many animals show no outward signs until they are very ill, or changes are picked up on a routine veterinary exam. Changes may include enlarged lymph nodes anywhere in or on the body, a greatly enlarged spleen, wasting, difficulty breathing, and extreme lethargy. A complete blood cell count may indicate abnormal (cancerous) cells present, although this occurs in a very small percentage of cases.
    • Diagnosis is generally by biopsy of a lymph node, spleen or fluid from the chest.
    • Treatment is by chemotherapy of the animal fulfills certain criteria that would make it a good candidate, Chemotherapy has been successful in about 75% of our cases, allowing life to be prolonged in a quality way for 6 months to 2 years.


    • This is a tumor of the pancreas leading to a high insulin production and a low blood sugar.

Adrenal Adenoma or Adenocarcinoma

    • This is a tumor of the adrenal gland.

Skin tumors

    • There are a variety of skin tumors occurring in the pet ferret. The most common are sebaceous gland adenomas, and mast cell tumors. Most of these should be removed particularly if they are ulcerated, bleeding, or have a rough surface.
    • Chondromas occur with some frequency on the tip of the tail as a hard round lump. They are generally benign, but may become large and bothersome and can easily be removed.


Toxoplasmosis is a disease which is sometimes spread through animal feces, especially cats'. It's nothing to worry about, unless you're pregnant, have a very young child, or have a weakened immune system -- it's very dangerous to a human fetus in the first stages of development, it may be dangerous to infants and toddlers, and it's a concern for those who are HIV+. Ask your doctor if you think you might be susceptible.
Toxoplasmosis has been reported twice in ferrets. Ferrets will not shed the toxoplasma organism to the extent that cats do, but if they are exposed to cat feces, they may contract the disease and shed very low amounts of oocysts.

Because of the devastating effects that Toxoplasma can have on a developing human fetus in the first trimester - you don't want to take any chance at all on exposing [a pregnant woman] to Toxo. So [someone in the household who isn't pregnant] inherits all litterbox duties for the next nine months. Actually, a pregnant woman probably stands a higher chance of getting Toxo from poorly cooked beef.