I'm finding such mixed opinions on this, even from vets! I'd love to know what everyone here thinks.
<font size="2" face="Verdana, Arial">The new monthly heartworm prevention medications are safer to use than the
older diethylcarbamazine (DEC) based medications. DEC could cause serious
illness and even death in a patient given the medication while harboring
heartworm microfilaria. Preventing this occurrence was the original reason
for annual testing. The newer monthly heartworm medications do not cause
serious reactions in the great majority of cases in which microfilaria are
present and are actually used commonly as microfilaricidal treatments after
the adult heartworms are eliminated. Due to this, many vets are comfortable
testing at longer intervals now. I think that the American Heartworm
Society recommendation is "every two to three years" at this time.
<font size="2" face="Verdana, Arial">Originally posted by griz:
The vet even surmised that the adults would eventually die a natural death, and being on the preventative was like being on birth control for the heartworms.