Monday, November 30, 2009

Heartworm In Winter?

If your veterinarian has your dog on year-round heartworm medication, and you live in a state where the birds actually fly south for the winter, you might want to consider changing vets or at least not following his or her advice on this matter.

Here's why: heartworm can only be transmitted to a dog if the heartworm nematode has completed the first part of its lifecycle inside the body of a mosquito. The first part of that lifecycle can only be completed if the temperature stays above 57 degrees for at least 45 days straight, both day and night.

To read more, see "The Billion Dollar Heartworm Scam " and "Year Round Dosing for Big Veterinary Profits."


Marie said...

I choose to keep mine on Interceptor all year long because it also kills roundworms and whipworms. Can I use a regular wormer? I suppose I could, but I like just giving a quarter-tab once a month (I get dosage for a larger dog and cut the pills).

If you stop the heartworm meds, the vet will want you to have your dog tested before putting them back on. The test runs about the same amount of money a 6 month dosage of heartworm preventative would cost for a terrier sized dog. So I just keep them on it all year long.

I live in a critter infested area, where rolling in and eating the various critter poops is great fun for my crew so thus the year-long treatment. I suppose if you're in an area without these kinds of tempations then keeping them on all year long would be overkill.

PBurns said...

As always, everyone can do what they want, but few dogs see more critters up close than my dogs, and I do not dose them every month (or even ever six months) for roundworm or hook worm. By the same token, by children were never dosed for roundworms or hooks worms as children "just in case" (in fact they never have), nor do I take regular penicillin shots "because you never know" etc.

To be clear, roundworms and hooks worms are NOT easy-to-get worms for a dog, are not fatal, and are easy to treat with across-the-counter medicine you can get at any pet store or from any pet catalogue. Taking a monthly prescription poison as a prophelactic is good business for drug companies, prescribers, and drug salesmen, but it is bad medicine for people and for dogs.


Viatecio said...

My classmate and I were just having a discussion about this recently.

She agrees with the idea, but the unpredictability of Ohio winters makes her keep her pets on it year round. I know a hard freeze can take out a good number of the bugs, but we've had a lot of warm days too. Is it the "better safe than sorry" thing? Sure, and she hates overusing drugs as much as I do. But, like you said, it's everyone's choice.

I mentioned it to my parents and got the "A) we're vaccinating her every year and B) we're heartworm-dosing her every month" response. It was not said in a nice way either. Mom is so deep in the vet's pockets it's not funny, and Dad (who has a bit of medical sense and understands how more than one way might be correct) is just too under her thumb to say anything to the contrary.

PBurns said...

As always, everyone is free to do what they want. A lot of people smoke cigarettes, for example, ingesting an insecticide directly into their lungs for years at a time with predictable results. Others, dose their dogs every month with an insecticide, and never once wonder if renal failure in a dog at age 12 is normal.

I can speak, with some authority on Ohio winters, however, as I lived there for three years and the winters there are as cold as hell and from November through May, there is no reason at all to give your dog heartworm medicine. See the maps here which were produced under contract by the company that makes Heartgard (Merial).


Viatecio said...

We're also in the suburbs and the city. While it gets cold for a spell, rarely does it dip to the snot-freezing temps I experienced living up near in the flatlands of Hardin county. Takes a good snowstorm to break the protective anti-weather bubble that's over this place. I do agree though. It's one more way to save, and it's not just about $$'s about the dog too.

People are free to be idiots in more than one way, but unfortunately, they might not be the only ones suffering from the consequences.

PBurns said...

It does not have to get very cold at all to end heartworm tranmission, and a warm snap does not make for an outbreak. Rememeber: **Heartworm can only be transmitted to a dog if the temperature stays above 57 degrees for at least 45 days straight, both day and night.**


None said...

" ... but I like just giving a quarter-tab once a month (I get dosage for a larger dog and cut the pills)."

You may be playing with fire Marie. Are the pills scored? Pills that aren't scored may not be safe to cut. Some of these pills will not work correctly if they are cut. Others are too difficult to cut or cutting is risky because an exact dose is so important.

Keep it in mind -


Gloria Cestero
Fly Creek, NY

john said...

i have used ivermectin for 20 + years and have lost a lot of dogs when i was dosing once per month not knowing the reason. I did some research and I backed off the ivermectin to once or twice per year and have had no heart worms and no more untimely deaths. Some Ignorance comes from believing people in positions of authority that are not necessarily of the integrity or intelligence to be giving advise even though they have a license. Also I have had vets identify a dog with heart worms and try to get the dog to be treated that did not have heart worms. They were trying to get business. A lab coat, title, or position, does not make the person's information reliable. Facts should be the choice for good decisions, and buyer beware.


Greeneville, TN