Heartworms and resistance!

In honesty I scream about this ALL the time.

YES -- HeartGuard and all the knockoffs have dosed ivermectin SO low (so it's acceptable to 'all' breeds -- because ivermectin causes such problems with herding dogs) that is' become ineffective.

 And any time a drug isn't used properly or strongly enough so that it actually KILLS the parasite/bacteria, etc. then when those parasites or bacteria *survive* that drug they become resistant to it and it doesn't work on them.

Tri-heart

Iverheart

They're knockoffs of HeartGuard -- and HeartGuard has already dosed the product SO terribly low that it's been causing problems for years.  I have posted about this endlessly -- and a lot of folks have pooh poohed it saying they've never seen the resistance ....

But then again, no one thinks about the fact that in Florida about 85 - 90% of all dogs picked up by Animal Control all over the state ARE positive.

Sorry -- I know that's not good news, but it's been a problem for years now. 

juliemule

but the country vet we use has not always added to the record when we purchased it I guess.

This makes me wonder if he was selling you phony product, or product that wasn't direct from the manufacturer. I've heard of knock-offs from China being sold online, so if the VET himself bought them, thinking they were legit, and resold them to you...I could see it happening.

I know there were lots of stories/comp[laints about phoney heartworm prevention being sold over the net and that the makers of the "real stuff" would not pay from treatment unless the product was bought from the vet.  I agree, maybe your vet bought some of the phoney stuff.  Or possibily, he got some bad.  That has been know to happen, tho rare.

 I used the old daily stuff for years and have used Interceptor ever since--except for the one bad horrible mistake of using ProHeart6 7 years ago and it killed my 4 year old golden retriever, Hunter--and I have neve rhad a positive test with either the old dailyes or the Interceptor.

We adopted  HOney Dec. 7, 2002 and found out a month later she was heartworm positive and had her treated.  She has been on Interceptor ever since, a checks out "clean" every year.  I am so sorry your dogs tested positive.

juliemule

. I heard the companies would reimburse, but the country vet we use has not always added to the record when we purchased it I guess.

That would really concern me. Where I work - we document EVERYTHING sold both in the computer, and on the paper chart. Even if it's just at tube of advantage - it's marked and double marked.

Have your dogs been tested yearly? 

I, personally, use interceptor on my dogs. We've tested negative each year in heartworm city.

I am just so frustrated. We are having two treated now, and the third dog starts treatment in two weeks. It is over $1200 just for the treatments. I don't know about the medicine, it looked official to me. The clinic just went to computers two years ago, and they only show a few boxes purchased, but I know they have been on it, I used to be a vet tech and know how important this is.

Our old malinois was positive, and our old lab/rott mix. Then Maddie the coon hound is also positive, she in only 2 years old. They have only recommended yearly testing last year, and my fault, I opted out thinking with the prevention, no worries.

So the newest recommended product is Advantage multi. Any one have experience or info on this? I really have no choice except to try it.

juliemule

I don't know about the medicine, it looked official to me.

The 'fakes' usually do. They are GOOD fakes. Maybe try contacting the company directly and pleading your case? The worst they can say is no. Maybe they'll do a partial reimbursement? It sucks that it really sounds like it wasn't your fault :(

juliemule

So the newest recommended product is Advantage multi. Any one have experience or info on this? I really have no choice except to try it

NOT my choice either. We use Interceptor, and that's the only thing I'd use.

The vet said interceptor, heartgard, tri heart all are not working. I checked with a couple other clinics and they all agree. To top it off our farm borders a wetland refuge.

When I adopted Bailey, he had heartworms. The treatment for it was absolutly horrible and very painful for him (not to mention VERY expencive). There is no way I'd risk givnig him anything I had any doubts about.

I use Interceptor, and he has tested negative for it every year since. I have no doubts that Interceptor deffinitely does work, and I will never use Heartguard (or any of the knockoffs) or Revolution. Way to many horror stories about it not working, and Revolution is just way to dangerous.

juliemule

The vet said interceptor, heartgard, tri heart all are not working. I checked with a couple other clinics and they all agree. To top it off our farm borders a wetland refuge.

I find that hard to believe -- Interceptor isn't known to fail because it's dosed FAR higher because milbemycin is SO much easier on the body and better tolerated.  That's why Interceptor (and Sentinel) are guaranteed not just for heartworm, but for hooks and whips as well (and it takes a far higher dose of ivermectin or any drug to treat hooks/whips than heartworm microfilaria).

 Heartworm microfilaria are pretty fragile -- that's why they've continually lowered the dose of ivermectin.  If you look at the dose chart for various different parasites -- heartworm microfilaria is the easiest to kill of all. 

But the goal wasn't to kill just microfilaria -- the *goal* was to make the drug acceptable to all dogs.  And have it "Hopefully" kill the microfilaria.  So the dose that's in HeartGuard, Tri-heart, etc. is SMALLER than the typical vet PDR dose charts of how much ivermectin to use to kill heartworm microfilaria

People have no real concept of what a huge moneymaker this is -- if you buy a bottle of Ivomec (which is the cattle/pig wormer) and then give the "dose" according to the Veterinary PDR for heartworm "prevention" (i.e., the dose to kill microfilaria) you can give that "preventive" dose to 14-15 dogs weighing 75 pounds each EVERY MONTH for the full 5 year shelf life of the bottle and you will STILL throw some away.

Price of bottle?  About $45-$50.  (it's the small bottle if you're looking it up)

Ok ... that's how much the drug costs at retail price.  Realize now you've just protected 15 dogs for five years for under $50.  Then multiply out how much it costs for HeartGuard for a 5 YEAR supply times 15.  That's a lot of money.  That's not even taking into consideration what the actual drug 'costs' to make ... this is just comparing retail costs. 

Then figure that the actual "dose" in HeartGuard, et al is far far LESS than that dose you'd give of the liquid ivermectin.  Because that "dose" of liquid ivermectin will STILL cause enormous problems in herding dogs. (This is how I *KNOW* all this -- I had a herder who was sensitive to ivermectin -- and I know exactly how much I gave me and how many times I tried to cut the dose in half to see if he'd be ok with it because at the time there WAS *no* milbemycin -- it hadn't been invented yet!)

Interceptor is, and always has been, a bit more expensive than HeartGuard -- but it's dosed like 10 times higher than even the original dose of ivermectin that was in HeartGuard.  And if you read that same veterinaryh PDR about milbemycin you'll find that milbemycin is tested "safe" at up to 100 times the dose of ivermectin. 

Why the huge doses?  Because they USE huge doses of these drugs for other things.  They use a dose of ivermectin that is 200 times *more* than the dose if ivermectin in HeartGuard to treat demodectic mange (and other parasites but the dose for deodex is g-normous in comparison to what's used for hooks, whips, ear mites and lungworm).  But that's why they've never marketed it commercially -- because they can't market it to ALL dogs.

Down here - it's required that the dogs are tested yearly. We will not renew a prevention if they are not tested - helps regulate, and stays in compliance with the manufacturer of the prevention. If your clinic did not require a retest, that would also raise flags, IMO.

Immiticide is VERY hard on the dogs - they've actually stopped making it. My rescue group has gone back to treating heartworms with heartgard/interceptor. It's a VERY slow process, but easier on the dogs. We get out heartgard straight from Merial, so I have no doubt it is the official stuff. We discourage our clients from buying online, to prevent this problem too (we offer price matching instead).

Best of luck to your furkids, I'm sorry you're having to deal with this 

ETA: Callie - our Interceptor is actually CHEAPER than heartgard.

juliemule

The vet said interceptor, heartgard, tri heart all are not working.

One thing to remember is that young heartworms (that have gone through their mosquito cycle) have a short period of about 45 days in which a "preventative" can kill them.  The young heartworm will not die if:

(1)  The "preventative" (alias young heartworm pesticide) is given too late (heartworm is too old) or
(2)  The young heartworm is not exposed to enough of the "preventative".

The latter can take place if the dosage is too low or if the heartworm is in a location of low blood flow.

Some folks use their "preventative" every 45 days and I do not like that idea.  By giving it every 30 days one gets two chances at killing the young heartworms.  I want to give as little chemicals as possible, but this is one area where I don't think it is worth it.  Of course, I live in Texas where we have to give a "preventative" year round.

Regardless of which "preventative" is used, testing should still be done yearly.  The only effective test for a dog on a "preventative" is the antigen test (detects mature adult females).  This is because the "preventative" will usually have killed all the microfilaria. 

Notes: 

(1)  The only tests available are for baby heartworms (microfilaria) or for mature adult females (requires several 6-7??).
(2)  If a dosage of a "preventative" is missed or given late, one must wait 6-months before testing to allow any young female heartworms to mature and become detectable.
(2)  Microfilaria are harmless unless a bunch die at once (can block blood vessels and lungs).  However, microfilaria that are sucked up into a mosquito (and develop there) are the way that this parasite spreads.
(3)  Neither young heartworms (injected by a mosquito) not killed by a "preventative" nor mature adult males can be detected by any current test.  REPEAT - Young heartworms and mature male heartworms are undetectable. 
(4)  Statistically it is possible (but unlikely) for a dog to have a large burden of just adult male heartworms.

CAUTION:  A dog on "preventatives" can have a few adult female heartworms (and any number of adult males) and still come up negative on all tests. 

erica1989

Down here - it's required that the dogs are tested yearly.

My vet requires it, too. He gets tested in the spring every year, and I usually buy more Interceptor then too. My vet will NOT give a prescription to buy online, I can only buy it directly from the vet... I'm sure they have some sort of reason for it, but its a rip off. Their prices for Interceptor are much higher than I've seen online.

 legally, they cannot decline your request for an rx (I know that's how it is in FL). Do they offer price matching, perhaps?

So is it safe to use the ivermectin liquid as a prevention?