I am not a vet but I have a thought you might consider as a possible answer to your question. Assume for a minute that the drug what ever it may be, is highly toxic to the worms. Normally, heart worms reside in the pulmonary arteries near the heart. If the drug kills or paralyzes the worm, they lose their position holding mechanism and are transported by blood flow to the lungs where they become a pulmonary embolism and usually the result of such a catastrophic event is sudden death. Most vets perform a simple (and usually relatively inexpensive) test to see if you dog (or cat) has heartworm before putting your pet on heartworm medication for just this reason. Again, not being a vet, I am not sure what strategy is used if your pet tests positive.
I am interested to know, by the way, what products you are seeing advertised that you can buy over the counter. Down here on the Gulf Coast of the U.S., HeartGuard (TM) is the drug of choice and it was my understanding that you had to go through your vet to get it. I would be worried that the products that you are seeing advertised on TV might be wishful thinking on behalf of the animal holopathic, healthfood industry that in the end would be ineffective and a waste of money. Please let us know more about the products.
Stephen G. Kayes, Ph.D.
Cell Biology & Neuroscience; 2042 MSB
University of South Alabama College of Medicine
Mobile, AL 36688-0002
(334) 460-6768 (Voice)
(334) 460-6771 (FAX)
>>> "RingMaster" <RingMstr at attcanada.ca> 05/01 4:50 AM >>>
I have been noticing a number of products advertised on Television that
prevent canine heartworm infection. However, they all warn that the dog
should be tested for heartworm BEFORE taking the product.
Is there a biological reason for not giving the preventive medication to a
dog already infected with heartworm? Or, is it simply a marketing ploy to
avoid an owner claiming that the medication did not prevent the heartworm