Emergencies ferret owners may face

Canine Distemper Virus (CDV)

Ferrets are highly susceptible to CDV. The disease is virtually 100% fatal in non vaccinated ferrets. Vaccinate healthy ferrets at 8, 11, and 14 weeks of age then annually using FERVAC-D. For ferrets over 14 weeks of age with no, unknown, or outdated vaccination history, should be given a series of two vaccines 3 weeks apart, then annually on the anniversary of the last booster.

Rabies Virus (RV)

All ferrets should be vaccinated against rabies at 3 months of age, and then annually thereafter using IMRAB-3.


Ferrets can be very wiggly and difficult to hold still for minor procedures such as nail trimming, administration of medications, ear cleaning etc. The recommended and humane way to restrain a ferret is by firmly grasping the skin along the back of the neck starting close to the ears, support the back against your forearm, stroke the abdomen in a downward direction to relax them and suspend them off the table. This results in the ferret becoming very comfortable and relaxed.


This is a common surgical procedure in cats used to remove the last bone of the toe and the associated claw. The anatomy of the ferret foot is very different from that of the cat. Because of these differences, ferrets should NEVER have their claws surgically removed.

Hair Loss

Alopecia (hair loss), can occur for many reasons including: (1) poor nutrition, esp. dog food diets; (2) summer heat and humidity will cause hair to thin; (3) during heat, female ferrets loose hair along back and rump due to the effects of hormones; (4) alopecia of the tail can be seasonal with hair loss in the fall beginning in late summer with regrowth in the fall. This type of hair loss in ferrets rarely proceeds further than the tail.; (5) endocrine alopecia begins locally along the back and becomes generalized. In males, this type of hair loss is most likely due to adrenal tumors. In females, this can be caused by adrenal tumors, ovarian tissue left behind at time of the spay, and other hormone producing tumors.


Ear mites may cause a dark, discharge in the ears. Affected ferrets often scratch the ears and shake their head. Bacterial and yeast infections of the ear canal may cause similar signs. Microscopic examination of the material from the ears (ear mite smear and cytology) is recommended to determine the underlying cause of the ear disease and hence appropriate treatment.
Sarcoptic mites can cause scaly, itchy irritation of the feet and skin. Skin scrapings may be recommended to identify these microscopic mites.


can cause severe disease including hair loss, sores from scratching and anemia (low red blood cell count) due to blood loss. It doesn’t take very many fleas feeding on a small ferret to cause enough blood loss to be fatal. Treatment may include removal of the fleas, iron supplementation and in severe cases, a blood transfusion may be necessary. Do not use over the counter flea products. Many of these products can be toxic to ferrets especially those ferrets that are anemic. Consult your veterinarian for safe flea control. Your ferret should be evaluated for intestinal parasites by a microscopic examination of the stool performed by your veterinarian. Ferrets are also susceptible to heartworms. Blood tests used for detection of heartworms in dogs and cats may be used in ferrets however false negative results are common. Ferrets should be given monthly heartworm preventative. (see Heartworm Disease).

Viral Diseases

Canine Distemper Virus: Signs of disease seen in affected ferrets include: loss of appetite; fever; discharge from eyes and nose; and rash under chin and in inguinal (groin) areas. CDV is 100% fatal in ferrets however this disease can be prevented by vaccination.

Influenza Virus (human flu) can be fatal in up to 100% of affected kits. It causes mild disease in adults with signs including runny nose, loss of appetite, spiking fever, and history of exposure to persons with the flu.

Aleutian Disease: This is a viral disease of minks. Signs in ferrets vary including: muscle wasting, black stools, enlarged spleen, fever, and hind limb weakness/paralysis. Other cases may show hyperactivity, aggressive behavior, and muscle wasting. No specific treatment is available other than supportive care.

Bacterial Diseases

Proliferative colitis is caused by Campylobacter sp.. Acute disease presents with bloody diarrhea and death in 3-4 days. The chronic form is more common and presents with straining; soft, greenish-black stools; frequent, painful defecation and weight loss. The colon becomes thickened and firm and may be detected on palpation of the abdomen during a physical examination. Diagnosis is made by surgical or endoscopic biopsy of the colon.

Simple colitis: Inflammation of the colon has many causes and chronically affected ferrets present with soft, frequent stools with no pain on defecation. Compared to proliferative colitis, the colon is not thickened.

Gastric (stomach) ulcers: Stomach ulcers are commonly seen in ferrets. Although in many cases, the cause is undetermined , the occurrence of ulcers is frequently associated with the presence of Helicobacter. Clinical signs are often vague with lethargy, teeth grinding, hypersalivation (drooling), loss of appetite and dark black stools (melena). Affected ferrets often respond favorably to treatment with antacids and appropriate antibiotics.

Ferret ECE “Green Mystery Virus” In early 1994 a mysterious disease occurred in ferrets and spread quickly, particularly in the show circuit. It was originally called “the greenies,” but its official name is “epizootic catarrhal enteritis (of ferrets)”. “Epizootic” refers to a disease which is epidemic in animals, “catarrhal” means it’s an inflammation of a mucous membrane, and “enteritis” means inflammation/infection of the intestine. It damages the mucosa (the delicate intestinal lining which is instrumental in absorbing nutrients and water into the body) resulting in diarrhea and excess mucous production. In severe cases there may be deep ulcerations and bleeding into the intestinal lumen. Stools can range from bright green, loose and slimy to dark red, black and tarry. It is characterized by the sudden onset of bright green or yellowish diarrhea. Note, however, that the green color just means that the food spent a very short time in the ferret’s digestive tract. Ferrets do get diarrhea for other reasons, and a single day of soft greenish stool is not something to panic about. No specific cause has been positively identified but it is suspected to be a virus. Ferrets who have had the disease remain carriers for six months, maybe longer. Carriers are those ferrets that have survived the disease and appear healthy but are shedding the virus in their stools and are therefore still infective to other ferrets.

This disease is very contagious. The disease can be transmitted by infected fluids from the body. It can be spread through the air on tiny fluid particles or by direct contact with an infected ferret. This disease can be transmitted form one ferret to another on a persons hands or cloths. The incubation period is about 2 days. The disease has a very high morbidity (number of animals affected by it) but a very low mortality (those that die as a result of infection). In ferrets under three years of age, that have no other major health problems, the disease is fairly swift, causing only a few days of slimy green stool followed by recovery in most ferrets. Many of these ferrets do not need any medications, but one should watch closely to see that they are eating, drinking and urinating. Early signs of the disease are vomiting, followed by lethargy, diminished food intake, and a “drowsy” appearance. If a ferret stops eating, becomes lethargic or dehydrated, then it may be necessary to give fluids either by mouth, under the skin or by intravenous injection. Some ferrets benefit from a more bland diet until the stools formed again, such as meat type baby food, or Science Diet A/D. Antibiotics may be given to prevent secondary bacterial infections. It may also be helpful to use an intestinal coating agents protect the intestinal tract and soothe potentially ulcerated areas. Older ferrets and/or those with other health problems, may be more seriously affected. Although the percentage of animals that actually die even in this age group is very small, the disease can take a much longer time to resolve. Older ferrets are more likely to become dehydrated and develop bleeding intestinal ulcers. These patients need more intensive nursing care and have to be watched very carefully. Another aspect of this disease observed in older ferrets that have recovered from the diarrhea stage of the disease is continued weight loss. This is associated with inadequate absorption of nutrients from the intestinal lining. The intestinal mucosa may continue to be abnormal for up to a year after the initial infection. These animals have good appetites and normal stools, but can’t seem to keep the weight on. Each pet has to be evaluated individually and dietary recommendations made by your veterinarian. Ferrets suspect of having ECE should be isolated, preferably in separate rooms from healthy ferrets. Food bowls, toys, and litter boxes can spread this infection and should not transferred between affected and unaffected areas. Litter boxes should be cleaned on a daily basis using 1% bleach solution. Individuals who handle infected ferrets or new arrivals should shower and change clothes before handling uninfected animals.
Remember that the signs of greenish diarrhea are not restricted to this disease. Other diseases that may cause profuse watery green diarrhea in ferrets include intestinal lymphosarcoma (cancer), parasites (coccidiosis), and eosinophilic gastroenteritis. The Department of Veterinary Pathology, Armed Forces Institute of Pathology is currently investigating this disease in hopes of finding its cause.

Splenomegaly (enlargement of the spleen): The spleen acts as a filter to remove old blood cells and as a storehouse for blood. In ferrets, the spleen also produces new blood cells. Generally, this process occurs only where there is a greater than normal need for these cells, (i.e., after hemorrhage, or during systemic infections). The most common cause of splenic enlargement in ferrets is an accumulation of massive numbers of developing red and white blood cells known as “extramedullary hematopoiesis”. Extramedullary hematopoiesis arises as a result an increased demand for either red or white blood cells. The spleen can also be enlarged in ferrets with bacterial and viral diseases and with cancer. A combination of diagnostic techniques such as blood cell and chemistry analysis, radiographs, ultrasound and microscopic evaluation of cells removed by needle aspirate from the spleen or tissue samples removed from the spleen by biopsy can be used to determine the cause of the abnormal spleen.

Cardiomyopathy in the Ferret: Cardiomyopathy (CMP) is a common cause of heart disease in a number of companion animals, including dogs and cats. CMP is a congenital problem in some lines of ferrets that manifests as ferrets get older. Cardiomyopathy is an insidious disease – the majority of the damage to the heart occurs long before the owner ever realizes that the animal is ill. The general defect in all types of cardiomyopathy is the same – death of cardiac muscle fibers, which are then replaced with scar tissue. Scar tissue does not have the ability to conduct electrical impulse or to contract like heart muscle fibers can. As more and more myofibers are lost, the heart weakens and can no longer pump blood efficiently. This results in the two clinical findings which are the hallmark of diagnosis of heart disease in the ferret: a) an enlarged heart, and b) a “backing up” of the blood due to the weakened heart’s inability to pump it effectively. The resulting syndrome is known as congestive heart failure. When the heart begins to fail fluid may accumulate in the abdomen, resulting in a swollen belly and/or in the space around the lungs or in the lungs themselves. If fluid backs up into the lungs, the ferret may initially show a soft cough. As the fluid buildup progresses, the cough may worsen, and the owner will generally notice a sharp decrease in the animal’s energy. In the end stages of the disease, ferrets have marked difficulty in breathing.
Hypertrophic cardiomyopathy is characterized by an overgrowth of fibers in the heart which also results in an inability to effectively pump the blood with the end result being congestive heart failure. The cause of hypertrophic cardiomyopathy in the cat is related to a dietary deficiency of the amino acid taurine. The same cause is suspect in ferrets. Taurine is included in sufficient amounts in commercial ferret diets and in premium kitten foods such as Hills Science Diet® and Health Blend®. Dog foods do not contain sufficient levels of taurine or protein to be fed to ferrets. Diagnosis of the disease is difficult in the early stages, but becomes progressively easier as the disease goes along. All of the signs (enlarged heart, fluid in the abdomen or around the lungs) can be seen on a radiograph (or “x-ray”), and this is the primary method by which affected animals are diagnosed. Diagnosis is based on clinical history and signs, chest radiograph, ECG and ultrasound of the heart. Cardiomyopathy is a progressive condition with no cure only treatment. Medications are given to decrease fluid accumulation in the lungs and abdomen and to strengthen the heart. Not all animals respond well to treatment. Dr. James Fox, in his book Biology and Diseases of the Ferret, reports that even when treated, the clinical course is fairly rapid, and treatment failures are common. This enforces the need to monitor your pets closely and bring any suspicions that you may have to the attention of your veterinarian immediately.

Heartworms: Just like dogs and cats, ferrets can get heartworms. Heartworms are parasites that are transmitted from one animal to the next by mosquitos. Once the heartworm larvae has entered the ferret from the bite of an infected mosquito, it travels through the tissues to the great vessels that carry blood from the heart to the lungs. Here, in these vessels the larvae grow to mature worms. These worms grow to a length of over 12 inches. It only takes 1-2 worms to cause fatal disease in the ferret. Initially, infected ferrets may show no evidence of disease. Affected ferrets may show signs of coughing, exercise intolerance, difficulty breathing, vomiting, lethargy or sudden death. Standard blood tests used to detect heartworms in dogs and cats often give false negative results in ferrets. Ultrasound is often necessary for accurate diagnosis of heartworm disease. Treatment is rarely successful and the disease is fatal therefore prevention is the key. Ferrets should be given monthly heartworm preventative just like a dog or cat. Heartgard® for cats is recommended for use in heartworm prevention for ferrets.

Ferret Insulinoma (Islet Cell Tumor): Islet cell tumors, also known as insulinomas, are the most common neoplasm in the ferret. These tumors arise in the “islets of Langerhans” – a group of special cells in the pancreas which produce insulin. Insulin allows the body’s cells to utilize the glucose in the blood. Excess levels of insulin produced by these tumors drive the glucose from the blood into the cells of the body, causing a dangerously low blood glucose level, known as hypoglycemia. Weight loss appears to be a common finding in affected animals, and is occasionally the only sign. Hypoglycemic ferrets may exhibit a wide range of clinical signs including: episodes of staring blankly into space, foaming and pawing at the mouth, weakness progressing to seizure, comma then death. The more advanced the disease is the more frequent the signs and the more severe. Diagnosis is based on clinical signs, low blood glucose and elevated blood insulin levels. Ultrasound may be used in some ferrets to identify tumors of the pancrease. Surgery to remove the tumors is an option in otherwise healthy ferrets however reoccurrence of the tumor at a later date is not uncommon. In animals where surgery is not an option, or until such a time as surgery is possible, medical management may be attempted by using a combination of prednisone and diazoxide. It is important to realize that this is only alleviates the clinical signs and only acts to prolong the life not cure the cancer. Sugary snacks and treats should be avoided. These aggravate the condition by stimulating more insulin production. In an emergency, honey or corn syrup in small amounts can be rubbed on the gums of a hypoglycemic ferret then as soon as they are more alert, a protein snack such as strained meat baby food or their softened normal food can be given. Food should always be available.

Ferret Lymphosarcoma: Lymphoma is a very common cancer in ferrets even in young ferrets. It is a cancer of the lymphatic system. Noticeable changes in affected ferrets include: swollen lymph nodes, enlarged spleen, muscle wasting, lethargy, poor appetite, difficulty breathing, chronic diarrhea and/or hind leg weakness. The diagnosis is from a combination of clinical signs, a complete blood cell count and a biopsy of affected tissues. Radiographs may be helpful in cases where the cancer is in the chest. Treatment using chemotherapy is often successful and may prolong life from months to several years. Ferrets should be examined regularly every six months by a veterinarian. Early diagnosis of disease gives a much better prognosis and allows you to make informed decisions about the health management decisions of all of your ferrets.

Skin Tumors

Basal cell tumors are composed of skin cells and may become one of any of the components of normal skin, including glands, hair follicles, or just simple sheets of epidermal cells. Basal tumors appear as small warty growths that may have a depressed center. They grow slowly, and are freely movable, as they do not involve structures underneath the skin. They are easily removed, and are most common on ferrets over the age of four.

Mast cell tumors are composed of mast cells which are involved in allergic reactions, releasing certain chemicals such as histamine which cause the redness and itching associated with hives and other allergic reactions. These tumors usually appear as flat, often hairless, small plaques on the ferret’s body. Because these tumors release histamine, they may cause the ferret to scratch them resulting in an
ulcerated or raw appearance. In most cases, excision is considered curative, except in the malignant form where it may metastasize to the spleen, liver or lung.

Apocrine cysts are not true tumors but are dilated sweat glands. These cysts appear as small, round, hard “bubbles” just underneath the skin surface.

Carcinoma of the apocrine sweat glands is a malignant tumor in ferrets that generally grows rapidly, and in contrast to most other skin tumors, often becomes firmly anchored to underlying muscle. It rapidly invades and destroys adjacent skin and may metastasize to the local lymph nodes, or the lungs, resulting in the death of the animal. While excision may be curative if caught early, masses of this type that have reached any size are associated with a much poorer outlook.
While excision of the vast majority of the tumors that we have discussed is curative, there is nothing to prevent a second basal cell tumor, or mast cell tumor, from arising in another site at a later date. Always have any tumor analyzed, one can not determine the type of tumor by external appearance alone.