Charlene,
Heartworm disease is a fatal disease transmitted by mosquitos.  If a mosquito
that is carying the young heartworm (microfilaria) bites one of your little
friends, the microscopic parasite is injected through the skin and over a
period of months travles to the heart and grows into a full grown heartworm
(they can be 5 inches long).  Just 1-2 in a ferret can cause heart faliure
(coughing, shortness of breath, open mouth breathing).
The preventative comes in a chewable tablet (beef flavored),a pill form, and
a liquid.  All of these forms are effective to prevent heartworm disease even
if your pet is bit by the mosquito carring the disease.  So if your ferret is
at risk (goes outside) its a good idea to give him/her the preventative.
Dr Weiss
Potomac Animal Hosp.
301-299-4142
[Posted in FML issue 1159]