|From: Bob Church
Q: "Bob! At the Ferrets 2000 offical pub, you mentioned you thought the next big plague to hit ferrets would be Aleutians Disease. The very next day, I heard Dr. Williams speak about it and I am now quite scared. Is it as bad as you think?"
A: I think therefore I am, and I am convinced it is the ferret's version of AIDS.
I cannot and will not address the veterinary aspect of this question because a) I am not well read on this disease, and b) I am not qualified because I am not a vet.
But I have extensively studied the effects of introduced disease into virgin animal populations, giving several papers and recently being asked to write a book chapter on the subject. So, from an evolutionary aspect, I think I can discuss a few things. Still, I will forward a copy of this reply to Dr. Williams in the hope he can better address the issue. If I were you (assuming he elects to reply), I would listen carefully to him and treat it as gospel. That is not just because the man in extremely intelligent, but also because he is an excellent pathologist and probably knows this subject better than most vets (I know he seriously impressed me, and I --for one-- am EXTREMELY pleased he has started posting so frequently on the FML!!! We are extremely fortunate!)
ADV (or Aleutian Disease Virus; aka Aleutian Island Disease) is a parvovirus which evolved in mink (Mustela vison), and to which they have more or less adapted. By this I mean the disease is not always fatal; some cases are very mild, some are deadly, but most are in that region of middle ground where it can become a serious problem if the mink is weak or stressed, but not usually fatal. This is a coevolutionary adaptation between the pathogen (the ADV virus) and the host (the mink); those strains of the virus which are especially nasty kill off the hosts and reduce their chances of being spread. Those mink who are more resistant to the disease survive and pass on the immunity to their offspring. The end result is, over a remarkably short number of generations, the disease becomes less deadly and the hosts become more resistant. Take measles for example; it is a mutated variant of the same type of virus which causes both rinderpest and canine distemper. When it first spread in Europe, people died by the thousands. Over a few generations, it became a serious, yet not necessarily deadly disease. Until Europeans floated to the New World, and found a virgin population; that is, a population never exposed to the disease. Tens of thousands of Native Americans were doomed. Now days, few people, including Native Americans, die from measles. Co evolution between host and disease has taken place; evolution in our time.
Mink and ferrets are kissing cousins in Weasel World. Because some fur ranches housed both ferrets AND mink, it was just a matter of time for a chance mutation to allow the virus to cross the species line. Like in the measles example, the disease is usually quite nasty in a virgin population (ferrets) and ultimately results in death. But that's not the problem as I see it. To me, ADV is very much like AIDS in that
1) it has a very long incubation period before it is expressed,
The first reason is really the one which scares the crap out of me. Unlike ECE, where the ferret contracted the disease rapidly after exposure, it can take years for ADV to be expressed, and by the time you realize your little bundle of dancing fur is sick, your entire house could have contracted the disease, dooming all.
The other thing about ADV which scares me is when the symptoms start being expressed, they can easily be misdiagnosed as a non-specific wasting disease, insulinoma, cardiomyopathy, renal disease and a host of other deadly things. It is possible many cases of ADV have been (and will be) misdiagnosed, and animals which are spreading the disease are still coming into contact with healthy ferrets. So, like when AIDS first hit in the USA, it can take a long time for the full extent of the disease to be known.
ADV, like the initial cases of ECE, is already spreading into the ferret population like a virgin ground disease. The effects are easily predictable; at first the disease will kill a tremendous number of ferrets, but ultimately, it will either burn itself out (doubtful) or both the disease and ferrets will co adapt. These are predictable results, but the problem is the large number of ferrets which will die before the predictions hold true. I don't want my guys to be a part of that statistic.
This may sound a bit like hyperbole, and perhaps it is; as I said, I am not a vet. However, if I am correct and this disease follows the same sort of pattern as any number of virgin ground diseases, including plague, distemper, ECE, AIDS, measles, smallpox, and many, many others, then you can expect that what you observed with ECE will also occur with ADV. I think it will be the next ferret plague, and in years to come, thousands of ferrets will be suffering as a result. I am sure Dr. Williams can easily explain this better than I, and fervently beg him to do so, perhaps also offering public heath advice in preventing exposure.
Bob C and 15 Mo' Virgin Ground Ferrets
Aleutian Disease Virus...in FERRETS
Other ADV Web-Site Pages
- Aleutian Disease
A Hidden Danger to Your Ferret
And for some history and a look further: