Ferrets are susceptible to a number of different diseases of the respiratory system. The symptoms of respiratory disease are similar, regardless of the cause. Some respiratory diseases can be fatal, and it is important to attempt to determine the cause of disease in order to determine a prognosis.
"In the ferret, canine distemper is often fatal."
Canine distemper virus is a paramyxovirus that can infect both dogs and ferrets. In the dog, canine distemper can cause severe illness. In the ferret, canine distemper is often fatal. The virus is normally spread through droplets in the air (i.e., from an infected ferret coughing or sneezing out infective virus particles that are inhaled by a susceptible). The distemper virus can survive for around half an hour on contaminated surfaces, so it can be spread by hands, gloves and cage furniture.
The key symptom of this disease is a purulent (pus-containing) discharge of the eyes and nose. However, the first sign in a ferret is often a rash on the chin or abdomen that is followed by development of swollen and crusty skin around the eyes and muzzle. Most ferrets with distemper will be lethargic, depressed and develop a cough. Vomiting and diarrhea with melena (black, tarry stool due to intestinal bleeding) may occur in some ferrets. Neurological signs (brain problems) may occur is some ferrets and include seizures, incoordination, muscle tremors, and partial or full paralysis. Bacterial infections commonly occur secondary to distemper, probably because of a compromised immune system in affected animals.
Initially, the symptoms of distemper are very similar to influenza (flu) but ferrets with distemper generally appear much sicker than those with influenza. Certain symptoms, such as hardening of the footpads (which give the disease in dogs the name "hardpad"), indicate that distemper is the cause.
Treatment is very rarely effective and the mortality rate is usually 100%. Supportive therapy such as antibiotic treatment, nutritional support and placing in an oxygen tent may relieve discomfort and ease the animal's suffering. However, because this disease produces symptoms that are similar to human influenza in ferrets, treatment should always be attempted.
"Vaccination is essential in any animal that may be exposed to the disease."
Vaccination is essential in any animal that may be exposed to the disease. A vaccine that only contains canine distemper vaccine is approved for use in ferrets. Only this vaccine should be used, rather than a "multivalent" canine vaccine product that also contains other organisms that do not cause disease in ferrets. Young ferrets should have three vaccination boosters in the initial immunization series, at 6-8 weeks, 10-12 weeks and again at 14-16 weeks of age. In subsequent years, the ferret should receive annual boosters.
Ferrets can have adverse reactions (anaphylaxis) to vaccination and it is always worthwhile for owners to wait in the veterinary practice for 20-30 minutes to ensure that acute breathing problems do not occur. If problems do occur, your veterinarian can immediately administer an antihistamine or other required treatment. Other vaccine reactions that may occasionally occur include a mild fever or diarrhea, but generally, these are transitory or short-lived conditions. It is wise to hospitalize and monitor a ferret having such a reaction.
Human influenza virus can affect ferrets, and infected ferrets can affect humans in close contact. Rather than the severe purulent nasal and eye discharge seen with distemper, influenza causes sneezing and conjunctivitis (inflamed tissues around the eyeballs and eyelids), with a watery discharge from the eyes and nose. Other symptoms may include coughing, trouble breathing, fever, anorexia and lethargy.
"Young and immunosuppressed ferrets can develop an infection of the bronchi or small air passages within the lungs."
In otherwise healthy adult ferrets, involvement of the lungs is uncommon. However, young and immunosuppressed ferrets can develop an infection of the bronchi or small air passages within the lungs (bronchitis or pneumonia). In such cases, antibiotics are essential to control secondary bacterial infections. These secondary infections can prove fatal to young ferrets; intensive supportive veterinary therapy is essential to prevent fatalities.
Other causes for respiratory problems
Bacterial pneumonia without an initial viral infection is uncommon but can occur, as can fungal lung infection in warm, humid climates. Systemic antibiotic or antifungal therapy is necessary to treat bacterial or fungal pneumonia. In order to determine the appropriate medication, it is necessary to identify the organism involved by use of a "tracheal wash". In this diagnostic procedure, a small amount of sterile fluid is introduced into the trachea and bronchi while the animal is under anesthetic, and then the fluid is removed for subsequent microscopic examination and bacterial or fungal culture.
Lymphoma, a form of cancer, can present as a respiratory problem if the tumor involves predominantly the lungs.
Cardiac or heart disease is fairly common in ferrets, and as the heart disease progresses, it will compromise lung function, causing coughing or difficulty in breathing. Heart failure in ferrets may be due to a disease called cardiomyopathy, or due to a heartworm infection. In the ferret, the first symptom of heart failure may be a cough or rapid breathing. If a ferret has these signs, especially if an infectious cause is not obvious, its cardiac function should be assessed. If cardiac failure is diagnosed, treatment with a diuretic, which increases urine output and removes fluid from the lungs, will relieve the coughing and respiratory compromise seen in heart failure.
"Cardiac or heart disease is fairly common in ferrets."
Trauma can cause respiratory problems either due to bleeding within the chest cavity, or from pneumothorax, in which air enters the space between the lungs in the thorax or chest cavity, causing collapse of the lungs. Following any trauma, it is important to take radiographs or x-rays to show whether there are any problems within the chest.