Heartworms and resistance!

 It is - you just have to be SUPER careful with the dosing. Make sure you check with your vet on what the proper dose is for heartworm prevention.

Also - if you have herding breeds, you may want to use extra caution, as some have an extreme sensitivity to ivermectin.

Yes it is -- but at this point I would wonder how heavy a dose of ivermectin you'd have to give in order for the heartworm TO be killed (in other words how strong the resistance is).  I honestly don't know how that would work -- and be cautious ... are your dogs herders?

Vets typically don't like to have people using ivermectin to do heartworm "prevention" because it's outside their control.  Treating heartworm with the frequent doses of ivermectin takes a long time -- and it's like I said ... in a case where there is resistance I'm not sure what the path would be there.

The thing you MUST be careful of -- if you are trying to *treat* heartworm infestation wtih ivermectin you have to know that ivermectin actually becomes addictive and it actually turns on the immune system and the body can "forget" how to function on it's own if the drug is removed too fast (that's why they use it to treat demodex -- it manipulates the immune system).  So you give it for a few months (I did it daily with the dog we had) and then wean it off.  It took me a year to get a clear occult test.  But someone else took her as a foster and decided not to give it to her daily (because it was too hard) and they just stopped giving it and she developed a huge infection.  I got her back and adopted her and had to treat the infection as well. 

How has your vet suggested treating the heartworm?

The treatment they have recommended is advantage multi and doxycycline on and off for six months. Then use the advantage as prevention.

I do have belgian malinois, a coon hound and a rottie mix. I talked with another vet today, one I worked for years ago, and he said he would use the ivermectin liquid, at a dose of 1/10 ml per 22 lbs, 1% dosage, once a month. He said this would treat as well as prevent. It is way cheaper, not safer, but I don't see treating them and putting them back on the same drug that is not preventing the parasite to begin with. He did say he doesn't believe it is an actual resistance, but agreed with the belief the dose is not effective.

I am just not sure what to do, but I have three that are negative, and have to do something before they end up infected as well.

Julie-- DO NOT use Advantage-Multi.  That's got moxidectin in it (ProHeart 6???? Caused all sorts of problems including IMHA, many dogs died) and I wouldn't use that for ANY reason. 

The dose your vet is suggesting is far larger than the dose that's in HeartGuard, etc.  And it's common to use it once a month.

BUT -- my problem with doing it that way it that the dog is then a "heartworm factory" for the other 30 days of the month.  See ivermectin (and milbemeycin) stay in the body only for 24 hours.  They simply kill ALL the microfilaria in the body THAT day.  But then if there are active adults generating new microfilaria then the dog has the potential to SPREAD more heartworm during that time.

This is why a lot of those who treat this way do it at least weekly or sometimes daily (the doses of ivermectin).

However -- if you are using the ivermectin as your prevention of choice, it's not likely to fail if you use it at an appropriate dose (not the hyper tiny dose that is 'failing';).  It's not a bad option. 

I use Interceptor simply because it's easy for me.  Currenly I don't have any herders so I don't have to worry about that part.

Years ago, I had a corgi/shelti mix who was EXTREMELY sensitive to ivermectin.  That was how I learned so much about this.  Additionally, my old vet was on the team that did research and development for ivermectin originally. 

 Realize -- Bayer (who puts out Advantage-multi) is owned by Ft. Dodge.  Ft. Dodge was the company who put out ProHeart 6 (and who never wanted to own any of the problems it created).  In honesty, I won't use ANY Ft. Dodge products at all knowingly.  Moxidectin is extremely nasty stuff -- you never now how long it's actually going to STAY in the body and this was where all the problems occurred. 

 Doing some reading, I've found that milbemycin oxime is what's in Interceptor. Milbemycin is also known as moxidectin.

I found this puzzling, and was curious what you guys though. Moxidectin is what's in Proheart 6 and Advantage Multi. Milbemycin oxime is what's in Interceptor that we all call safe and the best. I was looking for a large bottle of milbemycin, since I like having the option to treat whatever's here. 

jennie_c_d

I've found that milbemycin oxime is what's in Interceptor. Milbemycin is also known as moxidectin.

NO they are not the same.  Let me type from the "Pill Book Guide to Medication for Your Dog and Cat" (page 374:

"General Information:

Moxidectin is in the same group of macrolide drugs are ivermectin and milbemycin oxime, other commonly prescribed once-a-month heartworm preventives (see Ivermectin and Milbemycin Oxime) and is also derived from a Stretomyces soil-living bacteria."

They are RELATED yes, but not the same drug.  All three of them operate by affecting the nervous system of the parasite.  

But each are quite different in how they approach the parasite's nervous system.  Therein lies the difference.  Moxidectin has the worst reputation of the three. 

Historically (and I don't know 'why' this is and wish I did) milbemycin has NEVER been available in a farm strength.  I'd love to use it but it's just plain never been available that way.

 Ahhh. Maybe I was misreading.

What I know about moxidectin is that it was in ProHeart6 and ProHeart6 killed my 4 year old golden retriever almost 7 years ago along with many, many other dogs.  so many were killed or had such bad reactions the FDa "requested" they take it off the market.  I won't use anything that has it in the product.

I was debating using Ivermectin and just dosing it myself vs buying HW meds, because its cheaper. I don't THINK Bailey has any herder in him, he used to be on Heartgard(long time ago, when I first adopted him and didnt know anything about it) and he never had any issues with it, and he went through HW treatment without any severe reactions.

But... I decided not to because I wasnt sure if it was a safe choice or not, I kept hearing that Interceptor is the better/more effective of the two. When I have multiple dogs, I may consider it because it would be much cheaper... but not if it would put their health at risk.

Do they sell bottles of Milbemycin oxime? I know the Ivermectin is sold as Ivomec as a cattle dewormer at Tractor Supply... Ive tried to find a source of Milbemycin Oxime online but came up with nothing?

 I can't find it in a big  bottle. I buy ivomec, since I can treat anything non-herder that's heartworm tested.

Julie -- if you will email me (not a PM cos it's an attachment) I'll give you the dosing chart out of the Pill Book Guide to Medications for your Dog and Cat ... I have done that treatment and there are things to know.  I never post that dose chart -- it's just TOO easy for someone to misuse it.

Spazzy

I don't THINK Bailey has any herder in him

The problem with Ivermectin comes from a deletion mutation in the MDR1 gene.  There is a test now for the presence of this gene mutation.  Talk to your vet.