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.