Bacterial, Fungal, and Nutritional Diseases

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    Keeping your ferret healthy requires an understanding of the needs of these animals. These animals are prone to many different types of health problems, and it’s a good idea to take them for regular veterinary checkups to find any potential problems before they become untreatable or require more drastic treatments.

    While a young ferret may need to go to the vet only on an annual basis, barring emergency or illness, it is recommended that once a ferret reaches the age of 3 years, he begins a 6-month checkup regimen. The ferret should have blood checkups done annually to screen for disease as well as to give your vet a baseline for what is “normal” for that particular animal. Most diseases common to ferrets are treatable if caught early enough. Although the extra tests may seem costly, it can actually save you money in the long run.

    Ferrets are strict carnivores with very rapid passage of food through their gastrointestinal system, that is why they require diets with highly digestible protein and available energy with minimal fiber. This makes them very susceptible to diseases associated with poorly balanced diets, such as Yellow Fat Disease described in ferrets fed a high level of polyunsaturated fats and/or deficient in Vitamin E.

    Young growing kits are found dead or cry when handled, and are reluctant to move. Affected kits have firm swellings under the skin and prominent lumps. Immediate removal of the offending diet is needed and daily injections of Vitamin E.

    Prevention Is Better than Cure

    A clean living environment is a very important part of keeping your ferret healthy. Ferrets eat often and tend to eliminate frequently; therefore, the litter box needs to be scooped daily and scrubbed down weekly. Ferrets are very sensitive to many chemicals, so be cautious when choosing your household cleansers.

    Because ferrets snack all day long, it is necessary to keep their food bowl constantly full. It is also necessary to clean out these food bowls at least once a week because of the grime that tends to build up on the bowl.

    Adrenal Disease

    Another common and potentially fatal problem is adrenal disease. The adrenal gland grows in size and causes abnormal amounts of adrenal hormones to enter the bloodstream. Signs include hair loss, scratching, and swollen vulvas in females. This disease is commonly seen in ferrets around 2 to 3 years of age. The treatment for adrenal tumors is surgery.

    Aleutian Disease

    Aleutian Disease Virus is a parvovirus that can infect mink and ferret. ADV-F is a strain of parvovirus that affects ferrets. ADV is a chronic systemic illness characterized by wasting and nervous system signs. Some ferrets may be infected but will show no signs. Unlike parvovirus in dogs and cats, the disease is caused by long-term effects on the immune system, and antibody complex depositions in kidneys, gastrointestinal tract, liver and arteries, not by the toxins of the virus. The course of the disease is usually protracted, extending over 12 to 24 months. Suspect ADV if your ferret has rear limb weakness, fecal/urinary incontinence and head tremor. There is no specific treatment for ADV. Emphasis is on supportive care (fluids and electrolyte balance, proper nutrition.)

    Anal Prolapse

    Anal Prolapse is an emergency condition that is signaled by a ferret sliding across the floor, dragging his rear end, and sometimes whimpering in pain. It can be caused by the E. coli bacteria that can be transmitted from human to ferret and vice versa. Medication prescribed by a veterinarian can treat this.


    Ferrets are moderately susceptible to botulism types A and B, and highly susceptible to type C. The incidence of disease in pet ferrets fed commercially prepared dry or semi-moist diets is rare. Improper storage and handling of fresh meat diets leads to the accumulation of botulism toxin, which causes flaccid paralysis in ferrets. Treatment consists of administration of type C antitoxin and supportive care. A bacterin for the C. botulinum type C is available for immunization of mink and ferrets fed fresh meat diets.

    Canine Distemper

    While rabies are rare in ferrets, canine distemper is not and is almost 100% fatal in ferrets within 12 to 42 days after exposure. Once a ferret gets the disease, euthanasia is recommended to prevent the spread of the disease to other animals and end the animal’s suffering.

    Some of the sign of canine distemper include loss of appetite, foul-smelling yellow or green sticky eye discharge, swollen eyelids, green or yellow nasal discharge, swelling of lips and chin, thick brown crusts that form on the eyes, nose, lips and chin, lethargy, diarrhea, difficulty breathing, dehydration, convulsions, and, in the later stages, a thickening and hardening of the paw pads.

    Since canine distemper is an airborne virus, ferrets can become infected even if they don’t leave the house by inhaling the virus from your skin or clothing. Because the incubation period for canine distemper can be as long as 10 days, always isolate any new dogs or ferrets brought into your household for 14 days unless immunity to canine distemper can be ascertained.

    Cold and Allergies

    Ferrets have a very weak immune system and can catch a cold or the flu from members of their human family, other animals, or airborne germs. Ferrets can also suffer from allergies. A head cold that might keep you out of work or school for a couple of days can prove fatal to a ferret. Always keep away from your ferret if you have any sort of influenza or virus.

    If your ferret has an excess discharge from his nose, you can wipe it with a tissue to help ferret breathe and swallow. Running a cool-mist humidifier near his cage, or placing your ferret in a travel cage inside a steamy bathroom will also help to loosen up mucus in the lungs, throat, and nose. If the cold lasts a couple of days, and your ferret is off his food more than usual, you may need a visit to the veterinarian for antibiotics.

    Congestive Heart Disease

    Mitral value insufficiency and cardiomyopathy, resembling the feline cardiomyopathy, have been observed in ferrets. Clinical signs include exercise intolerance, soft cough leading to difficulty breathing, and lethargy. Auscultation, palpation and radiographs can detect fluid accumulation in the chest and abdomen. Normal ferret EKG measurements are similar to those of the cat. Ferret heart disorders are treated similarly to feline heart disorders, with diuretics, antiarrhythmic drugs and calcium channel blockers.

    Dental Disease

    Ferrets are prone to periodontal disease caused by the accumulation of dental calculus. Regular preventive dental care is recommended as for the dog or cat. Teeth damaged by various causes, such as chewing on cages or bones, may require root canal repair or extraction.


    Implicated Pathogens

    Ringworm (Microsporum canis and Trichophyton mentagrophytes) has been reported in young ferrets. Stored litter or shavings for nest boxes are often the source of infection.

    Signs & Symptoms

    The lesions characteristic of ringworm are similar to those described for cats. There are round areas of alopecia, and scaley crusts spread all over the body.


    Topical fungicides and time will clear up the crusty, hairless lesions while fresh nest box material will help prevent relapses. Griseofulvin (25 mg/kg ) may also be used with topical therapy in advanced cases. Humans are susceptible to dermatophyte infections.

    Epizootic Catarrhal Enteritis (Green Slime Disease)

    This is a highly infectious disease of the gastrointestinal tract, often leading to a large amount of green, mucous-type diarrhea. This disease is usually seen in ferrets that are new to the house (sometimes called “stress diarrhea”) or have recently been housed with strange ferrets. Any ferret showing this symptom should immediately be quarantined away from your other ferrets. The suggested treatment is to use aggressive supportive care (IV fluids, nutritional support, etc.) to keep the ferret strong, and the virus will have to pass on its own. Ferrets also commonly develop intestinal inflammation (enteritis), leading to diarrhea.

    Gastric Ulcers

    Ulcers are induced by stress in the stomach and can be frequently seen in ill ferrets. Hyperacidity has not been associated with the formation of ulcers, and the presence of Helicobacter mustelae bacteria may play a role. Diagnosis is based on clinical test. Gastric ulceration may respond to cimetidine therapy (5 to 10 mg/kg orally t.i.d.) or triple medication therapy (bismuth, ampicillin and metronidazole) recommended for Helicobacter infections.


    Although heartworms are parasites and not a disease, they affect the heart adversely and can be fatal if not treated. The number of heartworm cases seen each year in ferrets is increasing, especially in the southern states. Ask your veterinarian about heartworm preventive medicine, especially if your ferret spends any time outdoors.

    Heat Stroke

    Ferrets do not have well-developed sweat glands and are prone to heat exhaustion. Clinical signs include panting and inactivity. Hot and humid conditions should be minimized by adequate air circulation and/or cooling. Optimum temperatures are 40-65°F with a humidity range of 40-65%.


    Insulinomas are common in ferrets over 2 years of age. An insulinoma is a tumor in the pancreas, which causes it to secrete extra insulin, causing the glucose in the blood to drop. Signs of insulinoma include decreased activity, increased sleeping, weakness in the back legs, hypersalivation, and sometimes pawing the mouth. High insulin level will depress blood sugar to the point of collapse and coma. Routinely, ferrets with insulinoma are treated with corticosteroids.

    Intestinal Blockages

    These disorders are often caused by the ingestion of foreign objects. Hairballs are most common in the older ferrets. Signs of foreign object ingestion include loss of appetite, diarrhea, lethargy and sometimes vomiting. Very rarely will a ferret pass foreign objects unassisted. Surgical removal of foreign objects is usually necessary.

    Kidney and Cardiac Problems

    Kidney and cardiac problems are also common in ferrets. Kidney disease can be recognized by increased water consumption and increased urination. Heart disease is most common in middle-aged and older ferrets. Cardiac signs include weight loss, coughing, exercise intolerance, labored respiration, or shortness of breath. The long-term prognosis is poor.


    Lymphosarcoma is another common disease in ferrets that may be seen in young or older ferrets. Signs include decreased activity, weight loss, appetite loss, respiratory distress, and enlarged lymph nodes. Chemotherapy is generally the preferred treatment. The cause is unknown.

    Mast Cell Tumors

    Although these growths are benign, they cause intense itching. These tumors look like scabs, but they don’t go away the way scabs will. Surgical removal is the only available treatment.


    Implicated Pathogens

    Streptococcus sp., Staphylococcus sp., and Escherichia coli are the most frequent causes.

    Signs & Symptoms

    Mastitis frequently occurs in nursing jills in early stages of lactation. Examination reveals an enlarged, firm, slightly reddened mammary glands. Milk is expressed with difficulty. Hemolytic E. coli usually causes fulminating gangrenous mastitis, which is often accompanied by fever, lethargy, and extensive presence of the bacteria in the bloodstream.


    Aggressive and immediate attention to coliform mastitis includes surgical resection of the involved gland combined with ampicillin (10 mg/kg b.i.d.) and gentamicin (5 mg/kg, divided t.i.d.) therapy.

    Nutritional Diseases

    Ferrets are subject to some of the vitamin deficiencies, including thiamin (Chastek’s paralysis), Biotin (achromotrichia), Vitamin E (anemia), and Bitamin D coupled with a calcium-phosphorus imbalance (rickets). When ferrets are fed a balanced, formulated diet, no deficiencies have been reported.

    Zinc Toxicity

    Exposure to excessive levels of zinc via galvanized feeding dishes or by licking cage bars may produce zinc toxicity. Zinc, in the form of zinc oxide, at levels in excess of 500 ppm is toxic to ferrets. Ferrets decrease their feed intake and lose weight on high-zinc diets. Greater than 3000 ppm of zinc is lethal to ferrets within 2 weeks. Affected animals become anemic and rapidly lose condition. Treatment by eliminating the source of zinc contamination (acid-washed galvanized cages or bowls), decreasing dietary zinc, and providing supportive therapy is indicated.


    Obesity has become extremely common and debilitating in ferrets. Ferrets tend to prefer sweet-tasting treats; overfeeding of these treats is the main cause of obesity in pet ferrets. Obesity results in serious muscular, cardiac and liver problems. Lethargy and rear legs weakness are common signs of obesity. Discontinue feeding sweet and high-fat treats and dietary supplements.

    Posterior Paralysis

    Paralysis accompanied by urinary and/ or fecal incontinence may occur. Paralysis may be due to hemivertebrae, vertebral fractures, intervertebral disc disease, hematomyelia, or myelitis. Ferrets with no radiographic lesions and those with intervertebral disc problems have responded variably to steroid and nonsteroidal anti-inflammatory therapy. This condition can recur.

    Proliferative Colitis

    Transmission of the bacteria causing proliferative colitis is probably by the fecal-oral route, is believed to be similar to intestinal proliferative diseases of hamsters. The infectious agent(s) may be present in inadequately cooked feed. What exactly causes the disease has not been established.

    Signs & Symptoms

    Clinical signs of proliferative colitis are seen in ferrets that are less than 10 months of age. The animals have green to bloody diarrhea that may persist intermittently for over 6 weeks. Affected ferrets have poor appetite, dehydrated, thin, and have a partial rectal prolapse. The history, presence of the rectal prolapse, and the palpation of a markedly thickened colon in a young ferret are major diagnostic features. Since the condition is unresponsive to therapy, the diagnosis should be confirmed by biopsy, and/or necropsy.


    Supportive care with antimicrobial therapy are typical treatments of proliferative colitis in ferrets. However, antimicrobial therapy may not change the course of the disease if improvements are not observed after 48 hours of drug therapy. Metronidazole or chloramphenicol treatments for 2 weeks has been reported to be effective. Prevention is difficult without understanding the cause of the disease.


    Ptyalism is excessive production of saliva and is an extremely common complaint in ferrets. It is usually associated with nausea. This can be caused by lesions in the mouth or underlying diseases of esophagus, stomach or throat. Young ferrets are more likely to have ptyalism caused by ingestion of a toxin, caustic agent or foreign body. In older animals, the cause is often a metabolic disease such as insulinoma. Pawing at the face or muzzle that frequently accompanies ptyalism is a common sign of nausea. Many infectious diseases (canine distemper, rabies, botulism), as well as seizures, cause excessive salivation. Treatment is directed against the underlying disease. Some household cleaning agent and plants can also cause ptyalism.

    Pyometra & Vaginitis/ Vulvar Cellulitis

    Implicated Pathogens

    Generally, bacteria recovered from infections of the female reproductive tract include both gram-positive and gram-negative bacteria commonly found in the mouth and feces. E. coli, Streptococcus sp., and Corynebacterium sp. are frequently found. The frequency of infections of the reproductive tract is quite low in intact females, especially if they are on progesterone therapy.

    Risk Factors

    It is generally believed that these pus-forming diseases are the result of infections that spread to the reproductive tract. Jills are predisposed to these infections during estrus, when conditions such as poor sanitation and aggressive hob behavior may cause vulvar cellulitis and vaginitis, especially if foreign material remains in the vagina.

    If bacteria gain access to the uterus via the open cervix, then pyometra may develop when the ferrets cycle out of estrus. Jills suffering from pancytopenia due to Hyperestrogenism frequently have pyogenic infections of the reproductive tract. Vulvar inflammation can also occur in spayed Jills that are in poor physiologic condition and kept in dirty cages, or that are housed with intact hobs, which often attempt to breed neutered Jills or Hobs. Infections may develop as a result of repeated hormone therapy when hCG or GnRH is used to induce pseudopregnancy in Jills.

    Signs & Symptoms

    When the vulva is inflamed, it is swollen and often covered with a milky film. It may look much like it does during estrus. A vaginal discharge that is milky to purulent may be present. There may be no clinical signs associated with early vaginal or uterine infections, or obvious systemic signs (depression, diarrhea, anorexia, etc.) may be observed. A purulent vulvar discharge may be noted when the ferret is handled or palpated. Vulvar cellulitis is different from swelling associated with estrus. Physical examination, abdominal palpation, radiography and routine blood work can identify pyometra.


    Vulvar cellulitis may be treated topically with antibiotic/steroid ointments. Removal of the foreign material from the vagina, administration of localized and systemic antibiotics, and a change in the type of bedding or nestbox material are indicated for treating vaginitis. Jills with pyometra should be evaluated for Hyperestrogenism.

    If Hyperestrogenism is diagnosed, the Jill should be cycled out of estrus (see Hyperestrogenism below), treated with antibiotics and, if needed, supportive therapy including blood transfusions, should be administered. Once the Jill is stabilized, ovariohysterectomy and antibiotic therapy are required.

    Rotavirus Infections

    Rotavirus infections affects ferrets from 1 to 7 days old, causing diarrhea, dehydration and stunted growth. Kits look wet, and hairs from the head and neck are slicked down.


    Ferrets do not appear to be highly susceptible to salmonellosis. Salmonella enterica serovar Typhimurium has been found in ferrets with severe conjunctivitis, dysentery, rapid weight loss, and a fluctuating body temperature. The risks of medicating infected ferret need to be weighed against the risk of exposing humans or other animals to Salmonella. The risk of human infections should always be considered when investigating ferrets with dysentery.

    Subcutaneous Abscesses

    Implicated Pathogens

    Staphylococcus sp., Streptococcus sp., Pasteurella sp., Corynebacterium sp., Actinomyces israelii, and Escherichia coli cause abscesses of the skin (infected bite wounds during mating), and oral abscesses secondary to injuries. The main way of transmission is by a penetrating wound that leads to an infection.

    Signs & Symptoms

    Signs of an abscess may include swelling, draining tracts, and fever.


    Prevention of penetrating wounds is accomplished by minimizing the animal’s exposure to sharp objects in the cage and in the diet. Good husbandry practices can reduce the incidence of abscess formation. Abscesses are usually treated by drainage and flushing with dilute betadine solution. Systemic antibiotics are prescribed with local or topical therapy, especially when gram-negative bacteria are involved.


    Implicated Pathogens

    Avian, bovine, and human strains of mycobacteria can cause tuberculosis in ferrets, however, clinical disease is uncommon.

    Signs & Symptoms

    Clinically, infected ferrets may become emaciated and have paralysis of the hind limbs, which may progress to affect all limbs. Disseminated disease caused by Mycobacterium bovis is associated with weight loss, loss of appetite, lethargy, progressive muscle paralysis, enlarged liver and spleen, and death. Enlarged lymph nodes may be palpated.


    Euthanasia is recommended. Ferrets are susceptible to the same forms of tuberculosis as humans and may be potential sources of human infection.

    Urethral Obstruction

    Urethral obstructions are most common in male ferrets. They are often seen in conjunction with prostatic enlargement due to adrenal gland disease and can also be caused by urinary stones, infections, etc. Initial treatment is to relieve obstruction with a urinary catheter. Further treatment includes fluid replacement, correction of electrolyte imbalances, and treatment of the infection.


    Urolithiasis is a common occurrence in ferrets. The signs are similar to those observed in cats, although urethral blockage in ferrets is rare. Urethral obstruction is often accompanied by pyelonephritis. Medical treatment of urolithiasis is the same as that for feline urolithiasis and cystitis. Reducing dietary ash and providing adequate water may aid in decreasing the recurrence of uroliths.

    Video Credits: Pazuandfriends
    Image Credits: Mariposa Veterinary Wellness


    1. E.V. Hillyer, K.E. Quesenberry, eds. – Ferrets, Rabbits And Rodents: Clinical Medicine And Surgery
    2. Ehrhart, N., et al. – Pancreatic Beta Cell Tumor In Ferrets: 20 Cases (1986-1994) JAVMA
    3. Erdman, S.E., et al. – Clinical And Pathologic Findings In Ferrets With Lymphoma: 60 Cases (1982-1994) JAVMA
    4. Fox, J. – Biology And Diseases Of The Ferret
    5. Vickie McKimmey – Ferrets (Animal Planet® Pet Care Library)
    6. Barbara L. Oglesbee – The 5-Minute Veterinary Consult: Ferret and Rabbit


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