After years of going along with "the program" and feeding my dog a monthly dose of insecticide each summer, I've decided to take what I believe is a small risk with her health for what I believe is a larger benefit to her health.
I AM NOT GIVING GRACIE HEARTWORM PREVENTIVE THIS YEAR. The decision was not made easily. For years I've given Gracie three or four doses of chewable Heartgard during mosquito season. Last year I gave her three doses of Heartgard Plus. She just tested negative for heartworm so three doses were apparently enough to protect her last year. Maybe none would have been fine too.
I suspect the heartworm preventive manufacturers push a little too hard in selling their product to veterinarians, and in encouraging veterinarians to sell it to pet owners. I also suspect some veterinarians blindly go along with the program, while others exaggerate the necessity of heartworm preventive in many parts of the country in order to sell heartworm blood tests and preventive.
The active ingredient in Heartgard is ivermectin, which is an anti-parasitic insecticide; used primarily against worms. Ivermectin is used around the world, by humans, to combat river blindness and other conditions caused by worm infestations. Ivermectin does not kill adult worms in humans or dogs. It works by killing the microfilariae --- the tiny larval form of the worm. Ivermectin has helped a lot of people. It's also helped a lot of dogs in areas where heartworm is a big problem. Yet I don't think it's a big problem in my area or in many areas of the United States where it's pushed on easily-panicked pet owners.
Researching the subject online led to conflicting data. According to Wikipedia.com, heartworms can only go through their development stage in a mosquito if outdoor temperatures remain at or above 80 degrees F (20 degrees C) for approximately two weeks. Wikipedia says if temperatures drop below 57 degrees F (14 degrees C), development will not occur. Yet DogAware.com claims outdoor temperatures have to only be over 57 degrees F (14 degrees C), day and night, for one to two weeks for heartworms to go through their development stage in a mosquito!
It supposedly takes about six months after a dog is infected with heartworms by a mosquito for the infection to show up in a blood test.
After doing some Internet research and re-reading chapters about heartworms in Dr. Richard Pitcairn's "Complete Guide to Natural Health for Dogs & Cats (2005)," and in Dr. Martin Goldstein's "The Nature of Animal Healing," I decided against Heartworm preventive for Gracie this year. She is 12 years old and at this stage in her life I think it's more likely her good health will be harmed by several doses of heartworm preventive than by a heartworm infection.
Both Pitcairn and Goldstein believe a heartworm infection is a serious matter and will not outright advise against administering heart worm preventive, especially in areas whee heartworm is prevalent. Yet both veterinarians seem to think a heartworm infection is not a guarantee in an unprotected dog, and not necessarily a death sentence for a healthy dog with a strong immune system. Especially if only a few heartworms are present, or if the disease is detected early.
Goldstein suggests all dogs not on heartworm preventive be tested twice a year for the disease and that's what I intend to do for Gracie. Early detection could make treatment easier on the dog. I just had Gracie's blood tested this past week and the results were negative for heartworm. Still, mosquito activity in our area probably starts around May and ends around October. So I probably should be testing Gracie for heartworm around November and April, to properly monitor against heartworm infection in our area. Eventually I will adjust her blood testing schedule accordingly.
Blood tests are no fun for Gracie, of course. Yet I think two blood tests a year will be easier on her health than three or four yearly doses of even a "beneficial" pesticide.
Of course I have doubts about deciding against heartworm preventive for Gracie this year. For the most part, I believe this decision is best at this point in her life. I realize this decision could turn out very badly for Gracie and for me. If it does, I might never forgive myself but I I know Gracie would forgive me. She knows I only have her best interests at heart.
