I had an interesting conversation with my vet yesterday. He had asked me if the dogs were current on heartworm preventatives and I told him no. He said that enough time had not passed since their last dose of preventative so a heartworm test would be a waste of money (I appreciated this!) and then asked me why I had stopped giving it.
So, I blurted out, in a nearly hour long conversation, my fears with chemicals and giving too much as far as vaccines and flea meds and heartworm preventatives. I explained that the thought of so much being pumped into the dogs scared me, etc.. I appreciate this vet a lot, so when he said, "let me tell you what scares me" I sat down and listened.
In a nutshell, he stated that the topical flea preventatives and this new capsule (I forget the name of it) that you give orally are the things that scare him because these are in/on the dog for at least 30 days but what does not concern him is interceptor as it is a pill that is given once a month, or every 40ish days and is out of the dogs system in about 12 hours and is 1/32 of the dose used in (I am having a memory blank here....).
He compared it to smoking cigarette's. If you smoke 100 today, you aren't likely to get lung cancer, etc., but if you continually smoke several a day for all of your life, it is more likely to catch up with you. So, he said, give the topical flea meds if absolutely necessary, but don't use regularly. And give the heartworm pill once a month, as it is far less likely to cause damage versus a dog actually getting heartworm and having to go through treatment to get rid of heartworm.
Having said that, I am still undecided on the heartworm pill, we have a low incidence in this area (the vet said the clinic sees maybe 10 cases a year and there are 14 doctors and the clinic serves the greater East Bay) and will not use, as I have been, use topical flea meds regularly. I do, however, keep them on hand (for dogs and the cat) in case of emergencies and will use them if we have a breakout, like we did just recently.