As near as I can tell, you're talking about an injection of ivermectin, which is what we typically find in heartworm tablets. I think, but do not know for certain, that it is not licensed for that use in this country (as an injectable for dogs--though it is licensed as an injectable for cattle). I remember back when Ivermectin first came out in the 80's. Back then I had horses and we thought it was a magical dewormer because it was injectable, which is much easier than trying to shove something down a horse's throat, especially when, at that time, the something was a rubber hose you stuck up the nostril and down the throat to the stomach and then you squirted the dewormer directly into the stomach to make sure the horse got the proper dose. Now consider doing that every other month. No, the horses didn't think it was a good idea either. This was BEFORE paste wormers came out. In fact, in this country (USA), I think paste wormers were a direct result of ivermectin being pulled because it was killing dogs. It later reappeared in paste form and quickly became a preferred dewormer for horses.
What was happening and why was it pulled? It had to do with dogs in Australia. I'm going only by memory right now. Certain breeds of dog are sensitive to ivermectin and it can kill them. Collies are an example. There were a number of deaths of collie type dogs in Australia and the FDA responded by pulling it from the market here. But what they pulled was the injectable. Considering I still remember this thirty years later, after a brain injury, and despite not being a dog owner at the time, you can imaging what a big stink it was. Ivermectin did eventually return in oral form (a paste for horses and a tablet or chewable for dogs). It also returned as an injectable for cattle.
I suspect, but do not know for certain, that the dosage was adjusted to make it safer, though some dogs are still not appropriate candidates for it.
And that's why I think an annual vaccination for heartworm is such a "foreign" concept to Americans.
As far as how long ivermectin works, I know it can work up to six months at least. We give it monthly because it is easier to remember and because if you miss a dose when it's given every six months, you need to retest before starting up again. This is why if you miss one monthly dose it is okay to just get back on your schedule.
I did recently ask a vet what you should do when you miss a dose, ie wait for the next one or give the missed dose when you realize it. He said it was safe to give two doses even days apart, so you should go ahead and give it when you realize you missed it.
Of course, you shouldn't just take my word for it. You should ask your own vet to confirm this. (Establish a protocol for your own dog when you miss a dose, under your own vet's guidance.)
So with the comment that some vets in caring's area don't think it is necessary, I also wonder if their incidence is as high as ours. Some areas of the US are at greater risk than others, and I expect the risks from one country to the next may be different as well. For example, in my area, we are advised to give it year round. Where my sister lives, some vets will prescribe it for only half of the year. It's a lot colder where my sister lives, and is cold a longer part of the year (which curtails insect activity during certain months).
In this country, we have to have blood drawn for a heartworm test either annually or biannually or a vet won't prescribe the medication. The result has to be back before the drug is administered because the purpose of the test is to determine whether it is safe to administer. If the dog is already infected and the heartworms have reached a certain level of development, then are suddenly killed at that stage, the dead worms can cause blood embolisms that kill the dog. So the treatment for heartworms is different from the "preventive" even though the preventive doesn't really prevent infection, it just prevents the larval worms from reaching a certain stage of development where they can cause trouble.
Again, the disclaimer: I'm not a vet. I haven't researched this and provide no supporting evidence. This is what I remember from various past events, news reports and my own discussions with vets. Your situation may be different depending on your location and situation and you should consult your own vet before acting on anything I've said in this post.
Topic: Heartworm reminder (Read 298 times)