# Thoughts on Heartworm Doses? MOVED FROM GEN INFO



## llombardo (Dec 11, 2011)

I was researching heartworm in my area and found some info off the Heartworm Society page about when and how often to give preventatives. It makes sensd to me and I'm thinking that I'm going to switch the dosing based on the climate. They used Chicago/Illinois as an example so it's spelled out pretty well and I can't screw it up I'm slightly hesitant about 6 week intervals instead of a month but that makes sense to. I've also checked the average nightly temperatures and it is under 64 degrees in May, I haven't checked June, but that is where the 30 day after season would come in making the first dose July 1st. It also states that milk thistle should be given for a week after each dose, but how much of a dose do the dogs get of that? I'm not familiar with milk thistle at all. I've attached the article and opinions are more then welcome. 

Heartworm Season & Treatment | The Natural Paw


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## harmony (May 30, 2002)

I would check with a vet, but once a month sounds about right.


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## Sri (Apr 25, 2013)

*Thoughts on Heartworm Doses?*

Milk Thistle is cooling for the liver! 
I have used it for years for myself and the kids. This is awesome news for me that I can give it to my dog. 

I dont know about dosage. But it doesnt have any side effects even if used daily for a few weeks. So I would venture by weight I would give half of an adult dosage for starters. ( or pill if dosage is not listed) 


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## JeanKBBMMMAAN (May 11, 2005)

The Heartworm Society doesn't recommend climate dosing. Are you on the right page? American Heartworm Society t

The website you linked is an article from 2007. 

Here is what AHS says - 
Chemoprophylaxis: 
AHS recommends year-
round administration of chemoprophylactic 
drugs to prevent heartworm disease, control 
other pathogenic and/or zoonotic parasites, and 
enhance compliance, the latter being particularly 
important in light of the documented presence of 
resistant sub-populations.



> *Update*
> 
> Based on new information regarding possible reduced heartworm preventative efficacy, I now feel it’s best to give heartworm preventives year-round, not only for better protection against infection, but also to ensure that the manufacturer will pay for treatment should your dog become infected with heartworms.


DogAware.com Articles: Heartworm Prevention in Dogs she has good information and is a proponent of less meds and natural alternatives, but still gives hr dogs year round heartworm pills at the normal dose.


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## llombardo (Dec 11, 2011)

The article was from a link on that page(American heartworm society). I read the other article that was posted also. Heartworm is common in areas with Mosquitos present, which is when weather gets to be over 64 degrees at night, which is really in June. My question now becomes why dose the dogs all year round if that is the case? I don't know if it's right but it makes sense, it's another poison in their system for what purpose? I feel comfortable with the DE and other worms, do that is covered.


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## llombardo (Dec 11, 2011)

I am presently dosing all year long and I caught some heat on that, which made me look into it.


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## Blanketback (Apr 27, 2012)

"We strongly advise against giving heartworm preventives less often than monthly, or giving lower than recommended dosages. While this may have worked in the past, based on the original efficacy studies, it seems clear that it’s not working now."

DogAware.com News Archive: Heartworm Preventive Effectiveness

I do the May-Nov dosing up here in the land of waaay below freezing winters, but I give it every 30 days. That article also says there's a window of opportunity for the larvae, so I'm not messing around. Ugh, this is the hard time of year when we have to make all these decisions about how much poison vs how much risk. That's another good thing about -20, lmao.


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## llombardo (Dec 11, 2011)

Blanketback said:


> "We strongly advise against giving heartworm preventives less often than monthly, or giving lower than recommended dosages. While this may have worked in the past, based on the original efficacy studies, it seems clear that it’s not working now."
> 
> DogAware.com News Archive: Heartworm Preventive Effectiveness
> 
> I do the May-Nov dosing up here in the land of waaay below freezing winters, but I give it every 30 days. That article also says there's a window of opportunity for the larvae, so I'm not messing around. Ugh, this is the hard time of year when we have to make all these decisions about how much poison vs how much risk. That's another good thing about -20, lmao.


Well that article made me feel worse. It kinda stinks that the medicine I give is not 100 percent


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## Blanketback (Apr 27, 2012)

I'm sorry - but it made me feel worse too


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## llombardo (Dec 11, 2011)

Blanketback said:


> I'm sorry - but it made me feel worse too


I called the vet mentioned in the one article and they said that they were recommending April here but they pushed it to May. They are looking at weather and the general rule is 2 weeks of solid 60 degree daytime temps to start medication. They also go 45 days between doses. They also are starting to think that the heartguard medication has something to do with protecting dogs against heartworm and Lyme but are in the process of researching that.


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## Gretchen (Jan 20, 2011)

*Do you give your dog Heartworm preventative year round?*

The last dose of Heartgard I gave Molly seemed to make her lethargic. I was concerned and found this is a common side effect but then found an article that states a monthly dose of this stuff is not necessary depending on where you live in the U.S. Looking at the maps at the bottom of this link it suggests I use heartworm preventatives June through Dec for our region in CA, and I wondered if anyone else stops the meds during the winter and non-mosquito months?

Unknown Facts about Dog Heartworms


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## llombardo (Dec 11, 2011)

Gretchen said:


> The last dose of Heartgard I gave Molly seemed to make her lethargic. I was concerned and found this is a common side effect but then found an article that states a monthly dose of this stuff is not necessary depending on where you live in the U.S. Looking at the maps at the bottom of this link it suggests I use heartworm preventatives June through Dec for our region in CA, and I wondered if anyone else stops the meds during the winter and non-mosquito months?
> 
> Unknown Facts about Dog Heartworms


 
This is just so funny. I started the same sort of thread today, because I'm thinking the same way. I did call a vet and they are researching if lyme and heartworm are both controlled by heartguard, they suspect it is, but who knows anymore. The reason its year round basically boils down to making up for the owner not giving it the right way. If there are no mosquitos, how necessary is it, I want to know this too. The vet I spoke to said they look for 2 weeks of 60 plus degree days to start medication and they do every 45 days instead of every 30 days. Another article said they based it on 64 degree plus night time temperatures.

http://www.germanshepherds.com/forum/basic-care/433449-thoughts-heartworm-doses-moved-gen-info.html


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## Gretchen (Jan 20, 2011)

llombardo said:


> This is just so funny. I started the same sort of thread today, because I'm thinking the same way. I did call a vet and they are researching if lyme and heartworm are both controlled by heartguard, they suspect it is, but who knows anymore. The reason its year round basically boils down to making up for the owner not giving it the right way. If there are no mosquitos, how necessary is it, I want to know this too. The vet I spoke to said they look for 2 weeks of 60 plus degree days to start medication and they do every 45 days instead of every 30 days. Another article said they based it on 64 degree plus night time temperatures.
> 
> http://www.germanshepherds.com/forum/basic-care/433449-thoughts-heartworm-doses-moved-gen-info.html


Thank you, I'll read through here. I was painting for most of the day yesterday and didn't see your post.


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## llombardo (Dec 11, 2011)

Gretchen said:


> Thank you, I'll read through here. I was painting for most of the day yesterday and didn't see your post.


 
Well it isn't to much to read, maybe yours will get more replies. I'm interested in what Moms or Gator have to say, so hopefully they chime in.


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## Colie CVT (Nov 10, 2013)

In my region (Idaho), we used to tell our clients that between april/may to october was the time that you wanted to give the heartworm preventative. Basically when it was warmer and the risk of mosquitoes was higher. However when we had a cardiologist here, he did a few small studies on dogs in the area who came up positive for heartworm. The first year most came in from other states (the Katrina dogs I think factored in here a little). The next year the amount of dogs who never left the state but got it went higher.

This past year when we and other clinics did testing before refilling heartworm (if your pet has been off of the preventative for a 6 month period, you want to test to be sure they haven't gotten something) and we had a dozen dogs scattered throughout the region who came up positive that had never left the state and also were not showing outward signs of disease. The simple counter tests should have a built in freebie to whatever lab makes them to confirm any positive, but we had to get the immiticide in and treated a few dogs. It's a scary treatment if they get heartworm. 

If they are on it year round, you get it through your vet, and somehow they come down with it, the company will pay. Or at least I know Merial has that policy for their Heartgard. If you used to give your dog Interceptor (that is now Sentinel) you won't hurt your dog, even if they do have adult heartworms in their system. It doesn't do the rapid kill that ivermectin can do. But it basically would prevent any juveniles from making it to adult.

You can look into your region obviously to see what trends they see, what the vets generally recommend (basically like calling clinics to do price shopping but asking them questions instead lol). My dogs I keep on it year round. One, my golden is a blood donor and it is required that he does. And two, my dogs come all kinds of places with me and I know there are all kinds of gross parasites floating around this region. Heartworm preventatives help keep those gross boogers at bay lol. I really hated my parasitology class. >> Just... heebee jeebees.


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## wyoung2153 (Feb 28, 2010)

I give it year-round.. have always.


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## Stosh (Jun 26, 2010)

I live in TX so it's a year round preventative. Stosh gets an injection every six months rather than the monthly does orally


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## SunCzarina (Nov 24, 2000)

Year round since I live on the coast of Rhode Island, flaky coastal weather. Some years we don't even get a frost until mid december. Other years we'll have a January or February thaw where we don't get below freezing for a few weeks. 

Not worth it to me to have to rush over to the vet with 2 dogs for a blood test during a warm spell. Protocol here is blood test every 2 years if they're on preventative all winter.


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## gsdsar (May 21, 2002)

Year round for me. It's just easier to remember. Flea an tick is generally stopped during the dead of winter. 


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## BowWowMeow (May 7, 2007)

No, I begin Heartgard (NOT Heartgard Plus) in May or June (depending on the weather through November (again, depending on the weather). I do test yearly. I count back 40 days from the first consecutive days/nights above 57. 

Like topical flea applications, Ivermectin is a pesticide. As such it has its own set of risks.


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## llombardo (Dec 11, 2011)

BowWowMeow said:


> No, I begin Heartgard (NOT Heartgard Plus) in May or June (depending on the weather through November (again, depending on the weather). I do test yearly. I count back 40 days from the first consecutive days/nights above 57.
> 
> Like topical flea applications, Ivermectin is a pesticide. As such it has its own set of risks.


Your weather is probably very similar to mine. I know I read this but what is the difference between heartguard and heartguard plus? And give an example of time frame, how many consecutive nights above 57? Now it might be 65 during the day and 45 at night, do both have to be over 57? So if it's 60 degrees day AND night the first two weeks in June you would give dose July 10th or so? Average temps at night in May here are still under 55. Some people also go 45 days and a holistic vet recommended that to me today. So I was thinking July 1, Aug 15, Oct 1, and Nov 15. From what I understand there is that 30 day period that can bring you into Dec and if needed one more dose in Dec, but I'm thinking days/nights over 57 are long gone.


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## Neko (Dec 13, 2012)

We use Sentinel and it is cheap and one of the safest drugs so yep, year round.


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## Gretchen (Jan 20, 2011)

llombardo said:


> Your weather is probably very similar to mine. I know I read this but what is the difference between heartguard and heartguard plus? And give an example of time frame, how many consecutive nights above 57? Now it might be 65 during the day and 45 at night, do both have to be over 57? So if it's 60 degrees day AND night the first two weeks in June you would give dose July 10th or so? Average temps at night in May here are still under 55. Some people also go 45 days and a holistic vet recommended that to me today. So I was thinking July 1, Aug 15, Oct 1, and Nov 15. From what I understand there is that 30 day period that can bring you into Dec and if needed one more dose in Dec, but I'm thinking days/nights over 57 are long gone.


This is from the linked article:

Two other critically important features in the transmission of heartworm are:


The right temperature. During the time the heartworm larvae are developing from L1 to L3 inside an infected mosquito, which is approximately a two-week period, the temperature must not dip below 57*°*F at any point in time. If it does, the maturation cycle is halted. According to Washington State University heartworm report from 2006, full development of the larvae requires "the equivalent of a steady 24-hour daily temperature in excess of 64°F (18°C) for approximately one month."
Humidity and standing water. Mosquitoes are a rarity in dry climates


I looked at last years temps in my area we only had six nights in a row where the temp was 57 or above. I also read our county has mosquito control measures to prevent West Nile virus, and I also read about spacing doses every 45 days. Molly has handled the heartgard well until a few days ago. Its scary to see her so tired. I may start again in June and do every 45 days. She usually gets an annual blood test.


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## Gretchen (Jan 20, 2011)

Neko said:


> We use Sentinel and it is cheap and one of the safest drugs so yep, year round.


Florida is one of those states where it is recommended year round.
Maybe we could look into a different brand for treatment, like Sentinel


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## The Packman (Jan 31, 2011)

We give it to Elly May year round here in Tennessee. I don't she really needs it in the winter months but I'd rather be safe than sorry.

My thinking is...since she's a poop eater and with my luck and the fact I'm paranoid, I worry about her getting some eggs. If I remember correctly...our Vet told me that is not a concern but with my luck, I'd be the first documented case. I'd rather pay the $$$ and not have to think about it.


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## llombardo (Dec 11, 2011)

Gretchen said:


> This is from the linked article:
> 
> Two other critically important features in the transmission of heartworm are:
> 
> ...


It would be safe to say that the warmer temps start June 1st here. Memorial Day is usually still at about 40-45 at night. So if the days start to be consecutively warm June 1st the first dose should be within 30 days of that, making it July 1st, right? I know that I read a 30 day time frame for some kind if cycle.


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## BowWowMeow (May 7, 2007)

I count backwards 45 days. Depending on the year I've started as late as early July. Some years my dogs just get 3 tabs total. 

Heartgard Plus has deworming meds in it. I don't deworm my dogs unless they have worms. I do take in a stool check every year.


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## NancyJ (Jun 15, 2003)

I quit in the winter in a region that should have been safe by that map and got two dogs with heartworm. That was in 1997. I now give it year round. According to that map I should start in June and stop in November.

IF the two dogs who got the heartworms had less than optimal immune systems, that is news to me. Neither one had any allergy issues and one lived to be 15, the other 14 (A GSD and an ESS) and were healthy all their lives other than the heartworms.

FWIW, I am very cautious about using chemicals (garlic only for this dog with no flea and tick chemicals) and am a vaccine minimalist.


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## Angelina03 (Jan 9, 2012)

Miami is mosquito **** and it's never really cold for more than a few days. It's year-round for us, I'm not taking any changes. 


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## K9POPPY (Mar 6, 2014)

My vet suggests year-round, he says it not worth taking chances with the weather, it only takes 1 bite- Bob


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## Neko (Dec 13, 2012)

Sentinel is $5 a pill at dr foster and smith online or if you get the box, you can send in for $10 rebate. 

My big boy and my puppy both do great on it, no reactions.  

We did awful on trifexis and stopped immediately


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## BowWowMeow (May 7, 2007)

I don't go by a chart, I go by the actual temperature. 

My vet said the few cases he's seen of dogs with heartworm here are dogs that have come up (by adoption) from the south. He also said it's increasing around here because so many more dogs are being brought up from the south.

I am in a much colder climate than the Carolinas, however.


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## llombardo (Dec 11, 2011)

BowWowMeow said:


> I don't go by a chart, I go by the actual temperature.
> 
> My vet said the few cases he's seen of dogs with heartworm here are dogs that have come up (by adoption) from the south. He also said it's increasing around here because so many more dogs are being brought up from the south.
> 
> I am in a much colder climate than the Carolinas, however.


I'm in the same type of climate as you and I think that the dogs with heartworm are generally the ones brought from the south too. The temperature doesn't lie. Mosquitos are not going to be out under I think its 64 degrees, so 55-58 degrees is a safe number IMO. They say that the cycle is in motion and takes two weeks, but one day with numbers lower can stop that cycle. Does that cycle start all over or continue where it left off? I might start in June with mine, I think July 1st would even work, but I don't want to push it. I might even spray around my house for mosquitos this summer because I don't want them bothering me either.


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## JeanKBBMMMAAN (May 11, 2005)

I merged the 2 hw threads.


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## llombardo (Dec 11, 2011)

JeanKBBMMMAAN said:


> I merged the 2 hw threads.


Thanks. I was going to ask if that good be done.


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## DJEtzel (Feb 11, 2010)

I've never dosed all year long. I dose May-October, every 45 days with liquid ivermectin.

Eta. We do have a lot of hw in the area. Lots of chained dogs, lots of dogs coming up from the south, too.


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## llombardo (Dec 11, 2011)

I was thinking about it and the rescue group I worked with did not do anything as far as heartworm was concerned. I asked if the dogs were on medicine and they said it wasn't in the funds, but as the foster person I could do it on my own. Their thought process was they hoped the dog got adopted quickly so the owners could get it done. I don't even know if they are even tested now that I think about it. Lots of rescues take dogs from everywhere.


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