heartworm medication? yes or no?

whoa guys! thanks so much for all these really thoughtful and helpful insights and input, esp. janet rose for all the references!

rethinking this, and since I do live near the atlantic coast and have tons of marshlands near where i live, making skeeters plentiful, i will keep her on heartgaurd every 30 days year round.... and just give her milk thistle a few days before and after, and continue to get her tested yearly.

as with flea and tick medication, since i can obviously detect this to my naked eye easily, i will space out applying it to her longer than the recommended 30 days, and stop altogether during the winter.

however, i do have capstar in her emergency kit.

thanks again guys!  illnesses scare me....but medication scares me as well.....

(OT I've been on and off high dosage of prednisone for about 10 years, and HATE it!  I'm only 27 and had to get both my hips xrayed and a bone density scan already....however, every time i DONT take them, I end up in the ER.... so to medicate or not medicate is near and dear to me.... it's definitely not the money part....but i hate unnecessarily medicating her.... *sigh* a rock and a hard place.)

I live in Santa Fe and a foster dog I adopted a few months ago just tested positive for HW.  She was due for her annual and so got her checked, thankfully.  Like Denver it's not real common here either.  The Shelter does the HW test but it takes 6-7 months for the worms to show up.  THankfully she's stage 1.  SHe had 2 immiticide injections 24 hours apart and stayed at the vet 3 nights (charged for 2 nights).  CBC, chest xray, rimadyl, heartguard rx for 6 mos, and all in all it came to $600.  No excessive exercise for 4-6 weeks then another test in 4 months.  I had my other dog, plus my "new" foster dog tested and both are negative.  There's a high HW incidence rate in a small area in north central NM where she was found as a stray.  Mosquitoes are worse there because of the Rio Grande and agriculture.  I got my other dogs the pro heart injection which is supposed to be good for 6+ months ($45) then the HW test is $35.  At my vet Heartguard for 6 mos ($49) was a bit more expensive than the pro heart injection ($45) for a 60lb dog.

 I had fostered 2 Katrina rescue dogs with HW 3 years ago.  One died of heart failure (it was too late for her) and the other we treated with the longer term method of no immiticide, but instead higher doses of heart guard plus benadryl and aspirin.  It took several months but he eventually tested negative then got adopted in Chicago.

Last year I skipped the HW stuff for my dogs.  This year they're on it again.

 I would steer away from the injection. There have been far too many problems with that medication, including fatal ones....everyone has their own opinions but I would not use, or recommend to a client, something with such a sketchy record when monthly medication is much safer. It is back on the market now after the recall...but I want to see several more years without dogs dying for me to start trusting it again.

First, you do realize that this thread is a year old? 

MMEK's Mom

I got my other dogs the pro heart injection which is supposed to be good for 6+ months ($45) then the HW test is $35. 

Second, you couldn't pay me to use the ProHeart injection.  The first version killed or destroyed the health of many dogs, so it was taken off the market.  The manufacturer (Ft. Dodge) ran a smear campaign on the courageous FDA woman who got that version of ProHeart off the market.

This first version effected different dogs in different ways.  Some dogs had seizures before they left the vet's office after the shot.  Some dogs had kidney and/or liver problems.  There is constant strain on those organs.  Other dogs had their immune systems destroyed.  Some dogs had multiple shots before their owners realized that their kidneys or livers were failing.

The shot puts 6-months worth of pesticide into the dog's system with no antidote if something starts going wrong.  Not having problems on previous shots is no guarantee that there will not be problems with the next shot.  A considerable amount of the kidneys must be destroyed before you will starting seeing bad test results.

I am convinced that Ft. Dodge was (is with the second, limited-distribution version) experimenting on our dogs to test a delivery system for use on humans.  The shot is supposedly a "timed-release" system, but I have absolutely no trust in that release system.  You aren't supposed to use it on sick, old, underweight, etc. dogs.  What are you supposed to do if your dog has the shot and then gets sick?

MMEK's Mom

At my vet Heartguard for 6 mos ($49) was a bit more expensive than the pro heart injection ($45) for a 60lb dog.

My preference is Interceptor.  Both Interceptor and Heartgard (no "u";) are out of the dog's system within 24-48 hours, so there is not a constant strain on the kidneys and liver. 

MMEK's Mom

I had my other dog, plus my "new" foster dog tested and both are negative. 

The presence of the foster dog that tested positive means that these other two could be harboring immature heartworms.  It depends on your timing in giving HW meds.  Foster dog + mosquitoes + over 45-days without HW meds = the possibility that the other dogs will test positive in 6 months.

Please note that one has to have a certain number (I think it is 6-8) adult females before an antigen HW test will show positive.  There is no test for adult males.  The cheaper microfilaria HW test is unlikely to show positive if a dog is on HW meds - even if there are adult females.

It frightens me to know that a dog on HW meds can have several adult female heartworms, but have all tests come up negative.

I live in a small town about 60 miles southeast of Denver.

We do have a smaller likeliness of dogs getting heartworm, but it's not that much smaller. Dogs in Colorado are having high incidences with heartworm because so many owners feel Colorado's safer in that regard. It really isn't. We have areas of Colorado where mosquitos can be of abundance; Lincoln, Washington, Weld counties in particular.

Colorado is quickly coming up the charts as a high area for the problem.

My dogs have been on Interceptor year round for at least the last 10yrs; for one, the winters do not get as cold as they used to, I've seen bees in the dead of winter. For another, Interceptor helps control other worms as well.

You couldn't pay me enough to do the Proheart injection; I wouldn't care if it was $100 less then the Interceptor, I wouldn't do it.

 I do give heartworm pills, generally year round, because the winters haven't been getting as cold lately. I'm not sure what brands we have right now, but I know we have two different ones, one for each dog. I did used to split them for Max, because he hovered right around 50lbs, give or take a few. I will push it a few days in the winter, but I do generally keep going year round. A few years ago, the vet used to put on the bottom of the bills to begin it in April, but i've noticed more recently, they've switched to suggesting it year round.

MMEK's Mom

I got my other dogs the pro heart injection which is supposed to be good for 6+ months ($45) then the HW test is $35.  At my vet Heartguard for 6 mos ($49) was a bit more expensive than the pro heart injection ($45) for a 60lb dog.

This was an old thread, but what you've said deserves notice.

 PLEASE -- do some research on ProHeart 6 -- and plese don't be misled by doing this merely on cost.   ProHeart is not a good drug.  They took it off the market and have recently brought it back on despite a maelstrom of criticism.  The problem with the injection (and that means that pesticide stays in your dog's body ALL THAT TIME) is that they really don't know when the drug leaves the body, and there's a huge risk that you will either leave the dog unprotected or you'll overdose them.  It was the second and successive shots in most cases that caused the deaths of the many many dogs who died the first time the drug was out.

 Ft. Dodge is simply a huge powerful drugmaker -- and they don't want to lose the revenue this creates.  So they've brought it out in other parts of the world where there aren't the drug controls there are here and then used THAT "experience" to get it back on the market here. 

 HeartGuard tends to fail -- Interceptor is what most of us are using at this point simply because it does more than just heartworm 'prevention' but it is safer in higher doses than ivermectin (HeartGuard) so it's also effective with hooks/whips and other parasites. 

ProHeart itself isn't always the 'cause' of the death -- it simply created other problems with in the body -- most notably a disease called IMHA or immune-mediated hemolytic anemia (also called auto-immune hemolytic anemia or AIHA).  Several of us on the board have had experience with that disease and frankly, it's nearly always fatal.  There is an IMHA thread on here that is now in it's 40'th page (which is pretty incredible).

There's another problem with the Proheart. Moxidectin has a weird half-life, where it drops off very rapidly but sticks around at much reduced levels. There's two issues with this. One, it doesn't stay around long enough to affect heartworms. This is apparently what made it a candidate for the extended-release product. However, as Callie pointed out they have no idea really as to guaranteed levels in any individual dog. And personally the delivery system itself scares me. Ick.

Ironically, the livestock wormer that is based on moxidectin is marketed for its extreme safety levels and ZERO withdrawal. That's how fast levels drop. It works great with ruminants. It apparently goes through just fast enough but doesn't go off on detours into the bloodstream and whatnot. It hits the gi, takes all the nasties with it, and is nearly gone within hours, literally. 

That "nearly" is the second issue, however. Traces of moxidectin continue to hang around for quite a while, allowing parasites to "learn" to survive it. We've only had the product for a few years for sheep, and already there's significant resistance out there. Sheep raisers in some parts of the country are very nervous, because that's it - we have absolutely nothing left after Cydectin (moxidectin) is gone.

Up to now there's been little evidence of resistence in HW populations, but exposure to low levels of this one product can not only allow such an event to begin. It also opens the door for resistance to the entire class of drugs, the "avermectins." At the moment, the only monthly products we have available for HW are avermectins. 

The Heartgard website has a link that show the incidence of reported heartworm by county.

The county I live was low compared to some but I'm not going the stop giving Myrt and Frosty there monthly pill.

I do wonder if I should go with the Interceptor instead of the Heartgard.

I know that Myrt and Frosty started out on Interceptor and then I changed to Heartgard.

It's time to get them tested and a check up.