• I'm in Maine and I give heart worm meds (Interceptor) only from April - Oct. I have the retests done every spring as part of the annual exams & bloodwork. Since there is an issue with Interceptor production this year, I may need to switch, depending upon how much my vet has in stock.


  • @renaultf1:

    I'm in Maine and I give heart worm meds (Interceptor) only from April - Oct. I have the retests done every spring as part of the annual exams & bloodwork. Since there is an issue with Interceptor production this year, I may need to switch, depending upon how much my vet has in stock.

    If I was still back east and in the "freeze" zone, I suppose I might think about only doing it during spring/summer/fall… but regardless it is required by Vets in Califronia to do the blood test even if you are on year round. Not that you can't get it on your own on line... but if through a Vet, blood test is required.

    I am not sure that I agree if on year round the reason for blood tests, but I suppose that they are just "covering their butts"... and that I can understand.


  • It can be useful to know what the incidence of heartworm is in your area. In Ontario we saw an uptick in occurrences brought in by "Katrina" dogs. No good deed goes unpunished! 🙂


  • The other thing to remember about heartworm meds is that it works retroactively. That's very important to remember if you're not doing it year round. Also the newest (as in a few months old) guidelines from AVMA is that if you're on it year round, the vets should do blood work every other year.


  • @agilebasenji:

    The other thing to remember about heartworm meds is that it works retroactively. That's very important to remember if you're not doing it year round. Also the newest (as in a few months old) guidelines from AVMA is that if you're on it year round, the vets should do blood work every other year.

    Yes, the medication works to remove microfilaria after the dog has been bitten by an affected mosquito. Ivermectin (Heartguard) is less likely to cause problems if it is mistakenly given when the dog is already infected. It is perfectly possible to have a false negative test on an infected dog, particularly the inexpensive Diofilaria microfilaria test. OTOH, it is possible to have a false positive with the more expensive Occult test that tests for antigens of adult heartworms.

    Personally I prefer to avoid medication when it is not needed. Where I live, mosquitoes are not present year round, and the incidence of heartworm is rather low, so the likelihood of infection is slim. Heartguard in the warm months seems to me to be the safest approach. I have used Ivermectin for equine parasites the last thirty years without any serious incidents, so I am comfortable with using this drug.


  • Here in Florida, we have mosquitos year round, so are on Interceptor all the time, as well as flea treatments whenever we start to see the critters. I have never had any problems with heart worm meds, or known of anyone who did. I like the simplest meds, and don't use flea treatment at the same time as heart worm. Better safe than sorry, heart worm treatment is really rough and expensive.


  • Thanks everyone for all your good advice!


  • Just to be clear, starting with a puppy it should not be necessary to do a heartworm test, as the worms could not have time to develop yet in a young pup. I would ask your vet what is recommended as far as what age to begin the medication. Even if the pup got nailed by a mosquito in the first week of life, you should be fine without preventatives for at least 3 months!


  • On heartworm meds here as well… would never want to take the chance of my Kipawa getting heartworm.


  • @Kipawa:

    On heartworm meds here as well… would never want to take the chance of my Kipawa getting heartworm.

    Your chances would appear to be pretty low, even without medication. (unless you travel with him a lot). Reported cases in BC for 2010 (most recent I could find) were only 8, 2 of which were Vancouver, 1 each in Richmond and Delta, 4 in Kamloops. Given normal BC weather, I would suspect most if not all cases were contracted somewhere else. 🙂 Heartworm development in mosquitoes requires at least 2 weeks of temperatures about 27C with no nighttime temperatures below 14C. How often do you get that in your area?


  • I live on the south of Mexico, and have mosquitoes all year, all time, i give my basenji Maca heartguard all the time, and stopped some months and now she is positive for microfilaria.. the vet says she is oky and dont worth the risk so she is on heartguard again with not further treatment, Laika on the other side, tested clean. But now i wont stop any month. The vet was surprised because a lot of people dont give heartguard and has not microfilaria, and Maca take the whole life and for some months get affected.

    Well leason learned, now i have enough med for 3 months ahead for both girls.


  • @eeeefarm:

    Your chances would appear to be pretty low, even without medication. (unless you travel with him a lot). Reported cases in BC for 2010 (most recent I could find) were only 8, 2 of which were Vancouver, 1 each in Richmond and Delta, 4 in Kamloops. Given normal BC weather, I would suspect most if not all cases were contracted somewhere else. 🙂 Heartworm development in mosquitoes requires at least 2 weeks of temperatures about 27C with no nighttime temperatures below 14C. How often do you get that in your area?

    Strangely enough, we have a fair number of mosquitos starting right in May. I even see the odd one in my bathroom in November. We do have a pond in our backyard, which faces south. Might have something to do with it?


  • My pups are on HW meds year-round, and usually flea/tick too because I'm in Alabama and we've had fleas and mosquitos as early as Jan/Feb. You never know what AL winter will be like. We've always used Heartgard Plus - the dogs like it and I like that it also treats hooks and rounds.


  • Hello,
    We are originally from MA but now in SLC, UT. My B's have always been on Heartguard meds and we do it all year long and I have my B's test every two years. Results have always been negative. My 6 year old male B (Grady) started having seizures 6 months ago (summer 2013). We immediately went in for blood work and a vet check - no significant findings. I've been watching them more closely now and try to document everything I can…food intake, toxins, weather conditions, what happened that day of a seizure, stress triggers, etc. Grady has had 5 seizures and they are spread out since last summer. The seizures usually happen when we are asleep at nite and luckily only last a few secs to a minute or so. I want to AVOID medications for as long as I can and have started him on vitamins/antioxidants to increase his immune system. He is still a fun-loving goofy crazy dog otherwise. We were on Heartguard plus (chews) years ago but then converted over to Iverhart Plus for the past few years. Both my dogs have been on it but Grady has the seizures and my 13 year old female B hasn't show signs of seizures. She is going through the senior dog stages ... like more whitening near her nose, slowing down, getting sore easily, etc...but no seizures. I'm thinking that the "ivermectin" in the Inverhart may cause seizures and if this is the case...perhaps Grady has become very sensitive to this med since he has been on it for most of his life....I need to take him off of it and try something else for the heartworm prevention. I'm still hoping I can find out the cause of his seizures. Anna

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