Sukie wrote:
>Over 30 years ago a housemate's newly adopted dog developed canine
>distemper.  She had immediately gotten her vaccinated but an exposure
>apparently happened at or before the pound from which she adopted.  It
>was horrible, truly heartbreaking.
 
##Or there was also the possibility that the dog came down with distemper
from the vaccine itself.
http://www.thedogplace.com/library/articles38.htm
 
Here goes nothing on the JAVMA studies <g>:
 
First off let me explain a little about titers and what they can and
can t tell us.  I did some research on titers last week and hope I can
explain what I learned okay.
 
HUMORAL IMMUNITY, antibodies that circulate in the bodies fluid (this is
what is tested in a titer).
 
CELL-MEDIATED IMMUNITY, individual body cells that have learned by past
experience (exposure) what foreign invaders look like and mount a
response by manufacturing immune proteins.
 
MUCOSAL IMMUNITY which takes place in the thin mucous lining of the
mammary, respiratory, urinary, and digestive tracts.
 
Those are the 3 major immune system defenses at work in the body.  Of
those 3 the only current titer test is with Humoral Immunity.
Cell-Mediated immunity can be tested but it is expensive and difficult
to measure.  So we are only getting part of the whole picture with the
current titer test.  And low antibodies may not mean the animal is not
protected, it could mean that the animal has not been exposed to the
disease recently.  So are titers good?  Yes and no.  They could provide
a level of comfort to an owner who wishes to vaccinate less or has a
companion that has had a reaction or other health problems because of a
vaccine, or an old or sick companion who may get more risks than benefit
from a vaccine.  On the other side if an animal tests with a low titer
you still don t know if the animal is protected.  As far as I know there
is no titer level that has been established for a ferret.  You could
titer the animal then discuss with your vet the results and your options
based on the circumstances.
 
Which brings us to what do the titer numbers mean?  I was a bit confused
about this and found a site that explained it very simply:
http://www.obfocus.com/questions/qanda5.htm
basically the titer is the number of times you can dilute a sample of
blood and still detect the antibodies.  How do they determine what is
considered protective?  That I haven t found out yet!  I delved into this
because of the big difference in what was considered adequate in the 2
JAVMA studies I will be referencing.  Both studies were serum titers for
CDV & CPV in dogs.
 
The July 98 study went used serum CPV titers 1:80 and serum CDV titers
1:96 were considered protective and the results were: Thirty-three of
122 (27%; 95% confidence interval, 19.0 to 34.9%) dogs had a
less-than-protective CPV titer.  Twenty-five of 117 (21 %; 95% confidence
interval, 13.6 to 28.4%) dogs had a less-than-protective CDV titer.
 
The Oct 2000 study which was conducted by Lisa Twark, DVM & W.  Jean
Dodds, DVM (Dr. Dodds is very well known and respected in immunology, her
bio http://www.foxfirepublishing.com/doddsbio.html )
considered titers >1:5 an adequate antibody response.  The results were:
Of 1,441 dogs, 1,370 (95.1 %) had adequate and 71 (4.9%) had inadequate
antibody responses to CPV, whereas 1,346 of 1,379 (97.6%) dogs had
adequate and 33 (2.4%) had inadequate responses to CDV.
 
So you can see the differences in the tests.  I am still researching why
that is so, but don t know if I will be able to get an answer.
(different lab, different way of testing, or possibly the advancement in
veterinary science?)
 
I will be happy to forward the 2 studies to whomever would like to see
them in their entirety.  I am sending the link again for the challenge
and serology study that Schultz did because I feel that is a more
accurate test and because it tested out much further than these 2 did:
http://www.ivis.org/advances/Infect_Dis_Carmichael/schultz/
chapter_frm.asp?LA=1
 
I hope some of you found this informative and may go and do your own
research and make more informed decisions for all of your companions.
Here is a link to show you what some vet colleges are now teaching:
http://www.vth.colostate.edu/vth/savp2.html
 
~Amy~
[Posted in FML issue 4118]