Permission is granted to cross post this information, as long as the
post is taken in its entirety.
I was not going to go into details on the various tests, but someone
asked me to in a private email, so I will.
As I mentioned before, there are currently 3 diagnostic tests that are
commercially available for ferret owners to use.
United Vaccines offered the Counterimmuneoelectrophoresis, also called
the CEO or CIEP test for many years. In January, they stopped doing
the testing, but the Blue Cross Animal Hospital in Burley, Idaho is now
offering the test. They charge $10.00 per sample tested, and use the
same procedures that United did. Samples should be shipped to the
following address:
Blue Cross Animal Hospital
ATTENTION: Dr. Blau - CEP TESTS
401 North Miller Avenue
Burley, Idaho 83318
(208) 678-5553
For anyone who needs information on how to collect samples, I suggest
looking at the photo essay on the following website.
http://www.pooflinger.com/advtest.html
Some people prefer to have their vet draw the blood for them, and that
is fine. However, it will make the testing process more expensive.
The CEP test is an antibody test. This means that it does not test for
the virus itself, but for the antibodies the body makes in reaction to
the virus. Some people worry that testing for antibodies is not a good
way to know whether or not the ferret actually has ADV. I will try to
explain why they might think this, and also why I believe that point of
view is flawed.
When we are exposed to a virus, the body creates antibodies. Sometimes
the antibodies fight it off, and we do not get sick. So, in a situation
like this, testing for antibodies and finding them present does not mean
we are infected with the virus, just that we have been exposed to it.
As another example - when we vaccinate our ferrets against distemper
with either Fervac or Galaxy, we are actually injecting a small amount
of a modified version of the distemper virus into them. Their bodies
make antibodies against the distemper, and this is what protects them.
If you test a vaccinated ferret for distemper antibodies, you will find
them. But, this means the ferret has protection against the virus, and
not that it necessarily has the virus.
As a result, some people reason that if a ferret has ADV antibodies, it
might just mean there has been exposure, and that the ferret has actually
fought off the virus. And, while this is a possibility, it is an
unlikely one.
Remember, the antibodies that the ferret's body makes in reaction to the
virus are non neutralizing antibodies. This means they do not actually
fight the virus, or stop it from infecting the ferret.
Additionally, my own personal experience, as well as that of others who
have had ferrets that test positive for ADV is that when a ferret has
ADV antibodies, the ferret has ADV. So, how do I know this (that
ferrets have actually had ADV)? Because every one of my ADV+ ferrets
that had passed has been necropsied, and even in cases where the cause
of death was something other then ADV, the pathologist have found damage
from ADV to the organ tissue samples that have been submitted.
But, let me get back to the tests.
Probably the biggest downside to the CEP test is that it requires a
blood sample. Many people do not want to clip a claw short, and so
they have to have their vet draw the blood. Then, they have to pay
for express shipping to send it to the lab, and all of this adds to
the cost of testing.
The positive side is, the CEP test has been available and used for many
years, and has proven to be very accurate. No test is 100% accurate,
though, and that is why testing more then once is recommended.
The other 2 commercially available tests are provided by Avecon
Diagnostics, and while they are 2 separate tests, they have some
similarities. For people who want more information on these tests, I
have included a link to the Avecon website, but I will briefly give
some of the information here.
http://www.avecon.com/advabelisa.html
The Avecon ELISA, or Enzyme-Linked ImmunoSorbent Assay, is a test run on
a saliva sample that is sent in to Avecon. It has the advantage of being
run and read by a computerized machine, so they is no room for human
error in the reading process. If it is set up and done right, an ELISA
test is extremely accurate.
The Avecon Quick Chek is a home test you can run yourself on a saliva
sample. The big disadvantage of this test is it may be prone to
'operator error' if not done carefully. However, if the instructions
are followed carefully, it should be a fairly accurate test.
Some advantages of the Avecon test are that they are run on a saliva
sample, which can be easily collected by the owner without the help of
a vet. If a ferret is older or has other health issues, collecting a
saliva sample is less stressful to the ferret. Also, sending a saliva
sample is cheaper, since it does not need to be shipped via express
methods. The actual cost of the tests is close to what Blue Cross
charges for the CEP.
As I previously pointed out, no test is 100% accurate. The Avecon tests
are much newer, and have not had as long a time to prove their accuracy.
For the most part, when samples are collected carefully, and the tests
run per the instructions, they do seem to be fairly accurate, but there
is a slightly higher possibility of getting a false negative reading
from them.
Both of the Avecon tests are designed to react to a protein in
the ADV antibody that is only present when the virus is replicating.
Unfortunately, sometimes the ADV moves tissues, and goes dormant. When
this happens, the Avecon tests can return a negative result when the
ferret in fact has ADV. This is another reason that it is a good idea
to test all ferrets more then once, and several months apart. If the
ferret is going to shows or other public places, or is used for breeding,
then testing should be done several times a year. All ferrets used for
breeding should be tested before they are bred.
The University of GA (UGA) has a battery of tests they can do for ADV.
Currently, they have one test that is run on tissue samples commercially
available. This test, called the DNA in situ hybridization test. This
test is not usually used for diagnostic purposes, because it does require
tissue, either from a biopsy or necropsy. This test is a test for viral
DNA, rather then antibody, and is very sensitive and accurate.
UGA has also been developing their own ELISA test, and should have it
commercially available soon. This test looks for several proteins in
the antibody, and should give a positive result when antibodies are
present, whether the virus is replicating or not.
For some additional information on ADV tests and what they do, you might
want to read the ADV Updates I wrote and posted on the FML last year.
Kat Parsons put them up on the web with my permission. Here is a link
to the one that discusses the tests.
http://help4adv.terrabox.com/ADV-updates4.html
Also, you can see the article in the May/June issue of Ferret Magazine.
It also includes information about available ADV tests.
--
Danee DeVore
International Ferret Congress Health Issues Coordinator
http://www.ferretcongress.org
ADV - If your ferret hasn't been tested, you don't know!
For more information visit: http://www.ferretadv.com
You can help fight ADV!
Visit: http://help4adv.terrabox.com/
[Posted in FML issue 5218]
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