Quote:
Originally Posted by Ravyn  No, sorry, I won't be giving Loki any heartworm meds. I've done a lot of research on this and, I find, that more antibody tests per year is a safer way to go. Heartworm meds don't prevent heartworms. They are poisons that kill the larvae. It takes very specific circumstances for heartworms to even occur in a dog. Also, as the antibody test finds the larvae, you can then put your dog on the same heartworm meds that some vets recommend giving monthly. |
Okay, there is one false statement in this quote that is particular deadly for dogs: "Also, as the antibody test finds the larvae, you can then put your dog on the same heartworm meds that some vets recommend giving monthly." I repeat, that statement is FALSE.
The antibody test tests for the presence of adult female heartworms only. (See
https://vcahospitals.com/know-your-p...isease-in-dogs ) If you are going to use an antibody test and skip monthly heartworm medications, the antibody test needs to be done TWICE a year, and if it comes back positive, you will need to treat the dog with the medications to kill adult heartworms, NOT the monthly heartworm meds.
Below is the full quote from the article I cited above. As you can see, the tests are NOT perfect. Why would anyone living in a heartworm endemic area take chances with the health of their dog?:
Heartworm is usually diagnosed with a simple blood test. There are two main tests for detecting heartworm infection; one test detects
adult worms and the other detects
microfilaria.
Testing for Adult Worms: The American Heartworm Society recommends using the
Heartworm Antigen Test as the primary method of testing for adult heartworm infection. This test is specific for the adult female worm. Antigen is detectable by 6˝ - 7 months after infection and positive results are possible using some tests when there are as few as 1-3 adult females in the heart.
Antigen tests will be falsely negative if:
the infection has been present for less than 5 months (dog is infected but too soon for adults so there is no antigen present)
the worms are all male or all immature females (no adult female worms so no antigen present)
there are very low numbers of worms (level of antigen is too low to detect)
there are technical difficulties doing the test itself (test should be repeated)
Testing for Microfilaria: Any antigen test that is positive or “weak” positive should be followed up with a test for microfilaria. The presence of microfilaria confirms that mature adult worms are present in the heart and indicates the need for specific treatment to kill microfilaria. The best tests for detecting microfilaria are called
concentration tests. The preferred test is the
modified Knott's test, which involves using a centrifuge (a machine that spins the sample very quickly in a small circle) to concentrate the microfilaria; the other common test is the
filter test, which involves passing the sample through a very fine filter that traps the microfilaria. In both tests the microfilaria are detected and identified using a microscope.
Microfilaria tests may be falsely negative for several reasons including:
none of the adult worms are mature enough to mate and produce microfilariae
all the adult worms are of one sex so mating cannot occur
there are too few microfilaria in the bloodstream to be detected (mating is just beginning, or there too few adults to produce large numbers of microfilariae)