University of Glasgow School of Veterinary Medicine
Ferret Coronavirus in the UK: What We Know So Far...
Ferret coronavirus is a group 1 coronavirus, a member of the same family as feline coronavirus. This is relevant since much research has already been carried out on feline coronavirus, including here at the University of Glas-gow, and some of this information will be directly appli-cable to ferrets.
The enteric variant causes a highly contagious diarrhoeic disease called epizootic catarrhal enteritis (ECE); fortunately most ferrets recover from this. The systemic variant causes a serious systemic disease that is usually fatal (ferret systemic coronavirus-associated disease); this was first reported in the UK in 2012.
It is hypothesised that the systemic variant arises from mutations of the enteric variant within infected ferrets. But this only happens in a minority of ferrets infected with the enteric variant. It is not clear why some ferrets and not others will develop the systemic disease. In cats, young age, genetic predisposition and stress are all sug-gested as possible triggers for the viral mutation.
What are the Clinical Signs of ECE?
Infected ferrets initially go off their food; they seem lethar-gic and may vomit. Shortly afterward, they start to produce large volumes of green foul-smelling mucoid diarrhoea. Most animals recover within one week. However, older ferrets and ferrets with concurrent infections may become seriously ill.
What are the Clinical Signs of Ferret Systemic Coronavirus-Associated Disease?
Clinical signs are fairly non-specific so that this disease is likely to be under-reported. Ferrets may have GI signs such as vomiting and diarrhoea. Weight loss and lethargy are frequently seen, and some ferrets will also show neurological signs. This disease is readily mistaken for lymphoma or other abdominal tumours, since large masses are often palpable in the abdomen. These are in fact pyogranulomas.
How is Ferret Coronarvirus Spread?
Most likely, only the enteric variant will be transmitted between ferrets. It is mainly spread by contact with faeces from infected ferrets, both directly AND indirectly i.e. the virus can survive on inanimate objects that have been contaminated with viral particles e.g. clothing, hands, bedding, and equipment etc. This mearns that it is very difficult to prevent the virus being transmitted between animals. The incubation period i.e. the time that elapses between exposure to the virus and development of clinical signs is unknown but is expected to be very short i.e. within 2-3 days.
Can Ferrets Clear the Virus?
Our preliminary work at Glasgow shows that ferrets can clear the virus but can readily be re-infected. There doesn't seem to be long-lasting immunity to this virus. This is exactly what we see with feline coronavirus. We don't yet know how long it typically takes to clear the virus, and we don't know if ferret 'carriers' of coronavirus exist i.e. whether some ferrets can carry and shed the virus for life. This carrier state exists in some cats infected with feline coronavirus, and it causes a problem since they provide a continual source of infection.
Can Ferrets be Tested for Ferret Coronavirus?
Thanks to support from the UK ferret community, veterinary surgeons, and funding from Petsavers, BBSRC REP and UFAW, we have been able to analyse part of the genome of ferret coronaviruses that are circulating within the UK. We used this information to design a new test that reliably detects UK ferret coronaviruses. Please note that tests designed using genetic sequences from other countries may not be reliable in the UK. The new test is carried out on faecal samples, and uses PCR technology to detect virus RNA. We are making this test available now to assist with the dianosis and management of suspected ECE cases following a surge in demand. Please visit our website for the practicalities of summitting samples for this test: http://www.gla.ac.uk/vds or email us email@example.com
My Healthy Ferret has Tested Positive for Ferret Coronavirus. What Now?
This ferret is shedding coronavirus in the faeces, and is therefore infectious to other ferrets. Ideally, test-positive ferrets should be isolated from test-negative ferrets, either on their own or in a small group (< 3). They can be re-tested at 1 month intervals until they are clear. In time, a small group of ferrets should be able to clear the virus, provided there are no carriers within the group.
My Sick Ferret has Positive for Ferret Coronavirus. What Now?
There is no specific treatment for the enteric disease, ECE. Your veterinary surgeon will advise you on what supportive treatment is most appropriate. Most ferrets will rapidly recover from ECE.
There is no specific treatment for the systemic form of the disease and most ferrets die or are euthanased shortly after diagnosis. Immunosuppressive therapy can be attempted.
Can Ferret Coronavirus be Cleared from a Multi-Ferret Household?
We believe that most individual ferrets can clear the virus; however it is difficult and time-consuming to clear ferret coronavirus from a multi-ferret (> 3) household, given that the virus is highly contagious, and that ferrets can become re-infected.
To achieve this, the owner would need to have proper isolation facilities that can readily be disinfected. Ferrets should be placed into small groups (< 3) and barrier nursing must be practiced to ensure that the virus is not carried between groups on people or objects.
Good hygiene practices however can minimise the amount of virus in the environment. Small measures like weakly cleaning and disinfection (sodium hypochlorite i.e. bleach) of litter boxes, cages and bowls can be helpful.
Ideally, rescue shelters should identify and separate positve and negative ferrets and practice barrier nursing to prevent all ferrets becoming infected. Positive ferrets could be re-homed to single ferret households, or to known infected groups.
Breeding establishments: in cats we know that the virus is not transmitted to kitten in utero, and that kittens are protected from infection for up to 5 weeks. More work needs to be done to determine whether kits are also protected by maternal anti-bodies. If so, then kits could be isolated and weaned at an early age to prevent infection from the jill and other infected ferrets.
Should I Take my Healthy Infected Ferret to Shows?
Ferret organisations and show organisers may establish their own policies. Obviously, no sick animals, including ferrets with diarrhoea, should travel or mix with other ferrets. Ideally healthy ferrets with positive coronavirus test results or ferrets that have recently been in contact with infected ferrets should not mix with uninfected ferrets or ferrets of unknown coronavirus status. Handlers should take precautions so that they do not inadvertently transmit the virus from one group to another.
Current Ferret Coronavirus Research Projects at Glasgow
Ferret owners: we are currently interested in following groups of ferrets to establish the length of shedding, whether the carrier state exists and the interval to re-infection. If you wish to take part, please contact the laboratory: firstname.lastname@example.org
Vets: we are interested in analysing the genome of ferret systemic coronavirus. If you suspect you are dealing with a case of ferret systemic coronavirus-associated disease, please contact the laboratory: email@example.com
School of Veterinary Medicine College of Medical,
Veterinary and Life Sciences,
University of Glasgow
Tel: +44 (0) 141 330 8654 Fax: +44 (0) 141 330 5748