What you need to know about ADV and ECE – Ferret Diseases
ADV and ECE – Ferret Diseases: Aleutian Disease Virus or ADV infects the domestic ferret. Epizootic Catarrhal Enteritis (ECE) is a life-threatening illness that can infect ferrets. Both diseases can be deadly!
About Aleutian Disease (ADV): Its Origin and Description:
Aleutian Disease Virus, or ADV, got its name from the Aleutian mink, from which the strain evolved that now infects the domestic ferret. ADV is caused by a parvovirus. The parvovirus family is smaller than most viruses and is especially deadly because it infects rapidly dividing cells such as intestinal cells, bone marrow cells, and fetal cells. The parvovirus is not protected with a coating of fat as many other viruses are, and the parvovirus is especially hardy, and difficult to disinfect. The ADV virus is no exception.
There are several strains of ADV, suspected to differ in intensity. The strains that infect the domestic ferret can be transmitted through blood, feces, urine, saliva, and can also be passed from a jill to her kits through the placenta. There is also the danger of transmission through shared toys, bedding, and litter boxes, making it very unsafe to keep an ADV-positive ferret in a household of healthy ferrets. The virus can also be spread through human contact if a human handles an ADV-positive ferret and then handles another ferret.
A ferret with ADV can appear healthy for an extended period of time, making it impossible to detect if a ferret is ADV-positive simply by looking at him or examining him. The only sure detection is a blood test that determines whether or not ADV antibodies are present in the ferret’s system. Saliva tests are on the market, but frequently yield false negatives and false positives, which makes them less useful in determining a ferret’s ADV status with any degree of accuracy.
ADV’s unique method of infection is what makes it so puzzling and difficult to defeat. When a ferret is infected with the virus, the body reacts with a strong immune response and produces large quantities of antibodies. These antibodies do not destroy or weaken the virus. The antibodies instead bind and form complexes that are deposited into the body tissues, causing inflammation in major organs such as the liver, lungs, and kidneys. This causes progressive weakening and chronic wasting in the ferret, as well as ongoing symptoms such as lethargy, weakness, frequent bowel inflammation, frequent loss of appetite, black tarry stools (from intestinal bleeding due to inflammation), respiratory distress, and paralysis. There are a wide variety of symptoms, many of which are also associated with numerous other medical conditions in the ferret, making ADV diagnosis difficult based on symptoms alone.
The immune response also triggers the production of plasmacytes and lymphocytes, two types of immune cells, which accumulate in tissues. This strong immune response is one reason that an ADV vaccine has been so hard to develop; vaccines are meant to encourage the development of antibodies, but in the case of ADV, this is the problem, not the solution. What makes the virus deadly is the body’s reaction to the virus, and not the ADV virus itself.
It should never be assumed that because a ferret is not showing symptoms or distress, that it cannot be ADV-positive. Very healthy-looking ferrets have tested positive, and there are varying reports of the time it has taken individual ferrets to begin to show signs of illness from the time of infection.
What makes ADV such a threat to the domestic ferret population is the ability of an ADV-positive ferret to carry the disease for long periods of time while still appearing healthy. One ADV-positive ferret could infect all the ferrets in an unsuspecting home or shelter. A few infected kits could infect many more when they are held and mingled with other ferrets at a distributor or pet store, or when they are introduced to a household of healthy ferrets. Too many farms, distributors, and breeders are still not taking enough precautions against the spread of ADV.
Diagnosis is crucial, and any new ferret should be tested before being introduced to a new home or shelter. The saliva test detects levels of the antibody proteins in the ferret’s saliva, but saliva tests have not been held up to be very accurate. A blood test performed by a laboratory is the only sure way to know whether or not a ferret is infected with the virus.
The best defense against ADV is a good offense. Before bringing home a ferret from a pet store or shelter (many shelters now test ferrets and can provide you with the proper documentation), get an ADV test done by a vet and isolate the new ferret until you get a negative test result back. You don’t know where your new pet store kit has been, or whom it may have come in contact with between its birthplace and your home.
Research on ADV is ongoing, and the gains are slow but steady. Research has only recently yielded the discovery that ADV is a parvovirus – a major step both in pursuing a cure and in developing supportive measures for ferrets living with the disease.
ECE: The “Green Slime” Disease
Epizootic Catarrhal Enteritis (ECE) is a life-threatening illness that can infect ferrets. “Epizootic” means that it spreads rapidly, “Catarrhal” means “containing mucous” and “Enteritis” is inflammation of the intestines. The disease is often referred to as “The Green Slime” because it is characterized by loose diarrhea that is mostly green mucous.
Clinical signs of ECE begin with a bout of vomiting, which is often not noticed because it is watery and clear. The ferret may show signs of nausea accompanying the vomiting (pawing at the mouth repeatedly and gagging indicates nausea). Within 4-6 hours, the green, watery diarrhea begins to appear, and the ferret loses its appetite and becomes increasingly lethargic and weakens as the illness progresses.
ECE is most commonly seen after a new ferret is introduced into a family or shelter. If the new ferret is carrying the disease, the symptoms appear in the other ferrets within 2-3 days. In an outbreak within a colony or shelter, the rate of contagion is close to 100% because the disease is so transmissible.
However, if the disease is caught early and supportive treatment begins immediately, the ECE mortality rate averages less than 5%. This did not use to be the case, but more is known about ECE, including the fact that it is caused by a coronavirus. Supportive treatments for an ill ferret include subcutaneous and intravenous fluids, oral antibiotics to combat internal infection, and a bland recovery diet. Some ferrets have to be force-fed during part of their illness; others who refuse to eat at all have to have intravenous nutrients in the hospital until they can be fed again. Dr. Bruce Williams recommends simply warming Gerber’s chicken baby food for feedings during ECE recovery. Even duck soup may be too complex for their stomachs during this brutal illness. Continued chronic inflammation of the intestines can be a lasting effect of ECE, but can be treated with Prednisone. A vet should be involved immediately if you even suspect ECE!
ECE is characterized by a discouragingly long shedding time. Ferrets who have recovered from ECE can shed the virus for up to six months and endanger other ferrets. A ferret who has had ECE needs to be separated from other ferrets, and careful handwashing and sterilization need to take place between handling ferrets, cages, litter pans, and shared playthings to avoid transmission even after ECE recovery.
The disease is most commonly spread through oral/fecal contact. Contaminated cages, litter pans, toys, and bedding can spread ECE. The best way to avoid ECE is to know any other ferrets that your ferret is interacting with, and take care when introducing new ferrets into your home. Take care when handling kits in the pet store, and wash your hands and change your clothes between handling unfamiliar ferrets and handling your own. Remember that a ferret can be carrying ECE and have recovered and show no symptoms – so you never know who may have it! Be safe, and you won’t have to be sorry!
Looking for more Ferret Information? Try these: