Do You Know Giving A Dog Who Has Contracted Heartworm A Heartworm Medication Can Cause Illness Or Be Lethal?

by wendy on November 10, 2009

To save money would you skip having your dog re-tested for heartworm if you missed giving the dog its heartworm meds for a couple of months?
Would you be angry at the vet for not issuing a new prescription without a new, clear test when you failed to give the medication as indicated (monthly)?
Would you give the dog heartworm medication knowing it is possible that if the dog contracted heartworm during the lapse you could kill the dog?

No, I would have my dog retested 6 months from the time I missed the first dose, and then I would have it retested again 6 months later. I would put the dog back on Heartgard, not Interceptor because that is a different story until I had the dog retested in 6 months.
I had my dog to a vet school and to an internist because they couldn’t get a true positive or negative on her heartworm test. I was told the reason for that was possibly because she actually had heartworms but they were of the same sex so they weren’t reproducing and therefore there was no microfilaria present in her blood. I was instructed to give her Heartgard because it would have no effect on adult worms and it would prevent her from becoming reinfected.
Rescue groups that get old dogs that can’t withstand the treatment for heartworms frequently put them on Heartgard to prevent further infestation by the adult worms reproducing or from another mosquito bite.
As I said above, you cannot do this with Interceptor.

Maltese Mom

{ 11 comments… read them below or add one }

TD magnet October 31, 2009 at 9:20 pm

What a horror. I made a comment as well on the question. What would she rather have: $75 less in her wallet for piece of mind or the chance of a dead dog? This is exactly the same as people who do not spay their dog because of financial constraints then end up with 10 puppies to care for and an emergency c-section. Ignorance at its finest.

best heating contractor in Buffalo and Williamsville NY October 31, 2009 at 9:20 pm

My vet uses heart guard and they told me that you can give them only heart guard even if they have heart worms. They said that some of the older medications use to affect the dogs if they already had heart worms, but heart guard does not. They also said that when a dog comes in with heart worms they put them on heart guard as part of the treatment.
So in this case if my vet told me correct heart guard medication does not make a difference if the dog has heart worm already or not. In fact it helps.
I remember being worried about this before when I got my last dog so I made sure to ask this question and this is what they told me. I am sure some of the other heart worm medications may affect a dog in this way, but not heart guard.

ξBindi§ October 31, 2009 at 9:20 pm

If I rescue a puppy that’s under 6 months old during mosquito season, we start Heartguard right away. Over 6 months they have to be tested.
I raw feed and minimally vaccinate. I did skip Heartguard for one mosquito season, but decided I’d rather have my dogs on Heartguard a couple months out of the year than risk having to treat for heartworm. I do use plain Heartguard not Hearguard Plus which has other wormers in it.
Both dogs were tested before going back Heartguard this spring. We don’t use it year round in MN. Its generally recommend to put them back on when the snow start to melt and contine until after the first hard freeze. With the winters there really is no need for it all year round.

Music Producer October 31, 2009 at 9:20 pm

1. Yes, I know that treatment for heart-worm can sometimes be lethal…just like I know that heart-worm is 100% lethal.
2. I would never miss giving a pet medication, and I’ve never considered cost in caring for my pets
3. I would never be angry at a vet for properly following medical protocols.
4. Asked and answered; See #’s 1 & 2 above.

KKingS October 31, 2009 at 9:20 pm

No, I was not aware.
My vet is strict about the prescription preventatives they supply to us (Revolution.) I’m also very strict about sticking to the schedule of giving these preventatives. The mosquitos here are WICKED and I don’t dare send my dogs outdoors without heartworm preventative each month. I also buy those meds in bulk (like…the whole year supply for two dogs,) so that I save money and I don’t run in to financial crunches and am forced to skimp on my dogs’ health.

Curtis M October 31, 2009 at 9:20 pm

I wonder what people did before Ivermectin…dogs still existed in the south. People were creating the American Bulldog in GA and AL with no Heart Guard! I think heartworm infestation happens because of an already weakened immune system. I’m a “mostly natural” breeder but I know ALL natural breeders (no vaccines, no heart guard, just worming meds) who live in FLORIDA and have 13 and 14 year old GSDs…heartworm negative. They say it’s because of a boosted immune system due to feeding raw…I’m starting to go with that explanation…a good study would be helpful but who’d ever do that? *rolls eyes*. I use heartguard regularly, don’t skip doses!

__A_YAHO October 31, 2009 at 9:20 pm

No, I dont think its good to give a dog heartworm medication if it already has heartworms. The back of the package always says to have the animal checked first, so there must be a reason for this.

emilie. October 31, 2009 at 9:20 pm

I didn’t even know you gave it monthly.
My vet does some thing that’s like every 3 months, it’s an injection.
:|
Wow I’m stupid.

flutterb October 31, 2009 at 9:20 pm

yes. this is why the vet requires the test before giving out prescription.

Launi *Stand By Your Pit* October 31, 2009 at 9:20 pm

No.
No.
No.
ADD: The answer that was picked was so wrong. Good grief!!!!

Lioness October 31, 2009 at 9:20 pm

I have used preventative other than the stuff you can buy from the vet. (buying ivermectin for farm use and dosing it myself – I just buy from the vet, now) But, I never do so without testing my dogs. I never recommend this for other people, though, because most people don’t really know what they’re doing and don’t realize the potentially lethal consequences of messing it up. There are lots of ways to mess it up.
I also know that the heartworm larvae cannot survive in mosquitoes in temperatures below 70 degrees. In my climate, this means I don’t have to use it for more than a few months in the summer. But, in the summers here the mosquitoes are often thick.
I get annoyed with some vets for a lot of things, this is not one of them.

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