Just a clarification on yesterday's comments on heartworm - on rereading
today it was not as clear as I hoped....
 
>Now when you just give prevention to any adult ferret you run the risk
>of killing worms which you don't know about, and then setting up all the
>parameters for a fatal embolism.  Thus, all adult ferrets should be tested
>(preferably with the IDEXX SNAP occult heartworm test) before embarking on
>any prevention program.
 
The actual chance of killing adult heartworms with ivermectin (the most
commonly used preventative) is very small - while it can happen, it is a
very rare occurrence.  In most cases, the adults will live happily, and any
new larvae that are either injected by another mosquito who harbors them,
or any that may be produced by a patent infection (both male and female in
the same heart) will be killed.  Because of the low numbers of heartworms
in most affected ferrets, patent infections are not very common.
 
The biggest problem is that you are now thinking that you are preventing
heartworms, but since you have not run the test, you don't know that you
already have worms in the heart, causing progressive cardiac damage.
 
This is why if you are going to go to the lengths to start an adult on
prevention, you run the test first.
 
Bruce H. Williams, DVM, DACVP
Chairman, AFIP Dept. of Telemedicine
Armed Forces Institute of Pathology
Washington, DC 20306-6000
(202) 782-2392
[Posted in FML issue 3231]