# Heartworm



## David Frost (Mar 29, 2006)

There seems to be a significant problem with dogs on monthly preventative, contracting heartworm. The most affected area is Eastern Arkansas, Western Tennessee and Northern Mississippi. The problem is being studied by to prominent veterinarians, one from Auburn and one from Virgina. I've had two dogs, both one on Heartguard, the other on Advantage Multi, contract heartworm. Both have been successfully treated although, we almost lost a young GSD. A police department in West TN has had some problems as well as a SAR team. I've also heard reports of several private trainers, most for retrievers having some problems. WTN and East Arkansas is a hotbed for retriever trainers. 

At any rate, I recieved a letter today suggesting a protocol of Heartguard on the 1st of the month and Advantage Multi on the 15. It was recommended we continue this regimen until those studying the problem can come up with a better suggestion. We are also increasing our HW tests to semi-annual.

DFrost


----------



## ann schnerre (Aug 24, 2006)

so HW is mutating/evolving. that is just WONNNNDERFUL news, david 

(but thanks for the heads-up)


----------



## Candy Eggert (Oct 28, 2008)

David, here's a article that addresses the shortage of HW medication now. 

http://www.examiner.com/x-10613-Hou...d9-Heartworm-treatment-is-now-in-short-supply


----------



## Maren Bell Jones (Jun 7, 2006)

I'm thinking about writing the author of that erm..."article" (which just seems more like a blog piece?) as there are inaccuracies.



> and the *slow kill method* *which can take up to six months* by using heartworm preventative medication (e.g. Heartgard) and supplements to boost the dog’s immune system.


From the American Heartworm Society:




> ALTERNATIVE THERAPIES *Long-term Macrocyclic Lactone Administration *
> 
> Continuous monthly administration of prophylactic doses of ivermectin, moxidectin and selamectin is effective in reducing the life span of juvenile and adult heartworms. The older the worms when first exposed to macrocyclic lactones, the slower they are to die. So, the adulticidal effect of macrocyclic lactones generally * requires more than a year of continuous monthly administrations and may take more than two years before adult heartworms are eliminated completely*. In the meantime, the infection persists and continues to cause disease. Therefore, long-term continuous administration of macrocyclic lactones generally is not a substitute for conventional arsenical adulticide treatment.


From: http://www.heartwormsociety.org/veterinary-resources/canine-guidelines.html#11

From the same site on the lack of efficacy of heartworm preventative:



> *Reports of Lack of Efficacy*
> Lack of efficacy (LOE) of a heartworm preventive product is defined by the Center for Veterinary Medicine of the Food and Drug Administration (FDA) in the USA as a dog testing heartworm positive while consistently receiving heartworm prevention. There are many possible reasons for reports of LOE, including failure to administer sufficient preventive, failure to administer the preventive at the appropriate time interval, failure of a dog to retain a dose and failure of absorption of active ingredient. There is also biological variation in how hosts within the same species metabolize a drug as well as how parasites respond to a drug. Thus, the exact cause of a reported LOE of a product is extremely difficult to determine.
> Most LOE claims can be explained by compliance issues, either between the clinic and the client or the client and the pet. It is possible for an animal to become infected by missing or receiving a delayed administration of just one dose of a heartworm preventive product. The likelihood of this occurring is increased in endemic areas where infection challenges are exceptionally high when compared with other sections of the USA. Highly endemic areas typically have warm temperatures most of the year, an abundance of standing water and substantial mosquito populations. Many of these areas also have large populations of wild canids, with most of the animals infected with heartworms providing a large reservoir of infection. In addition, manufacturers have improved the sensitivity of heartworm antigen tests during the past decade and more animals with low female worm burdens are now being detected. The increase in the number of LOE reports to the FDA during the past several years has lead to concerns of possible heartworm resistance to the current heartworm preventives. First, it is important to understand that parasites do not become resistant to drugs, but rather, product use under specific conditions inadvertently selects worms with resistance genes. These populations of surviving worms are called resistant strains. Some conditions are known to favor the selection of resistant strains, as occurs with trichostrongylid nematodes of small ruminants and with horn flies. Limited refugia (i.e., worms with wild-type genes), a direct life cycle, treatment of entire groups of confined individuals, and the presence of heavy parasites burdens reduce the refugia and support the concentration of selected, resistant genes. Thus, the shorter the life cycle of the parasite, the more rapidly the resistant-gene-selection process proceeds. If we examine heartworm infection using the same selection factors, we see a converse scenario. Factors such as a long life cycle, relatively light worm burden, an indirect life cycle with mosquitoes as vectors, a large refugia of infected but untreated pets and wild canids that roam freely throughout their territories, treatment of dogs singly rather than in large groups, and pets that travel widely with their owners do not favor the selection of resistant strains. The epidemiology, treatment patterns and abundance of refugia of parasites such as heartworms ensures the wide distribution of large populations of heartworms that are not under strong selection pressure, and their wild-type genes serve to dilute any resistance genes that exist in geographically different worm populations. These conditions greatly decrease the likelihood of widespread emergence of resistant heartworm strains and any resistant strain would likely remain localized. Professional and client education are perhaps the most important factors to consider in addressing the reports of apparent lack of efficacy of preventive products. The complex biology of the parasite, the effect of changing environmental conditions that affect vector populations, the dynamics of host (wild and domestic) populations, and even the dynamics of human interactions with their pets are also relevant. In the face of the many variable factors, it is critical that veterinary practices ensure that clients understand the risk of heartworm infection in their area and provide their pets with appropriate heartworm prevention, i.e., consistent year-round administration of preventives.


----------



## Candy Eggert (Oct 28, 2008)

:roll: I was posting about the medication shortage not the effectiveness.

http://news.vin.com/VINNews.aspx?articleId=14447


----------



## Jerry Lyda (Apr 4, 2006)

David I use Ivomec for cattle and swine. I've had no HW issues. Lost is very low. I bought my bottle 3 yrs ago for $37.50. The cost is a little higher now, 40 something.


----------



## Maren Bell Jones (Jun 7, 2006)

Candy Eggert said:


> :roll: I was posting about the medication shortage not the effectiveness.
> 
> http://news.vin.com/VINNews.aspx?articleId=14447


Yes, I know, but the article said it took up to six months with the slow kill method, which is an alternative method sometimes now being used because of the shortage of immiticide. Just need to make sure people don't get the idea that you can just put them on ivermectin for a couple months and problem solved, as that's not the case.


----------



## Candy Eggert (Oct 28, 2008)

Maren Bell Jones said:


> Yes, I know, but the article said it took up to six months with the slow kill method, which is an alternative method sometimes now being used because of the shortage of immiticide. Just need to make sure people don't get the idea that you can just put them on ivermectin for a couple months and problem solved, as that's not the case.


Gotcha


----------



## David Frost (Mar 29, 2006)

the Vet I had treat my two dogs didn't have a problem obtaining the medication for treatment. Although one veterinarian did suggest the "slow kill" method. That is what about cost us a dog. We were fortunate he didn't die. We then put the dog through the more traditional heartworm treatment. 

The problem with hw in dogs that are on a preventative is not yet understood by the veterinarian community. 

DFrost


----------



## Candy Eggert (Oct 28, 2008)

David Frost said:


> the Vet I had treat my two dogs didn't have a problem obtaining the medication for treatment. Although one veterinarian did suggest the "slow kill" method. That is what about cost us a dog. We were fortunate he didn't die. We then put the dog through the more traditional heartworm treatment.
> 
> The problem with hw in dogs that are on a preventative is not yet understood by the veterinarian community.
> 
> DFrost


One of disturbing points of interest in the last link I posted was that the company that makes this medication will do a "triage" of sorts based on "need". They will determine case by case what dog gets the medication!? Maybe phone consults with the vets? 

I can only assume that PSD's will be exempt based on public safety, so might be the reason your vet had no trouble David? 

It's troubling when the cure is almost worst and in some cases deadly than the disease. Does your vet recommend PDS"s be taken out of service while being treated? I've heard that the method to kill HW is quite stressful on the dog's system.

We're grateful that in So Cal we don't have HW problems that I'm aware of. If I was traveling out of state with the dog's, I'd prepare with the preventatives months in advance. What a nasty little problem to have to deal with!


----------



## David Frost (Mar 29, 2006)

Yes, dog is on strict kennel rest for, I'm pretty sure, six (6) weeks. The vet I use for treating heartworm, keeps them overnight, after treatment. Treatment is given in three stages, I think one week apart. In 22 years, I've have 2 dogs test positive prior to the lastest two. The first two were spread out over a 15 year period. The last two were within months of each other. 


DFrost


----------



## Candy Eggert (Oct 28, 2008)

David Frost said:


> Yes, dog is on strict kennel rest for, I'm pretty sure, six (6) weeks. The vet I use for treating heartworm, keeps them overnight, after treatment. Treatment is given in three stages, I think one week apart. In 22 years, I've have 2 dogs test positive prior to the lastest two. The first two were spread out over a 15 year period. The last two were within months of each other.
> 
> 
> DFrost


Are the dogs that you quoted on/were on the preventative and still tested positive?! That would be really disturbing if that's the case. 

Either way given the number of dogs you have/had under your command, those are really low numbers. 

Best of luck with the last two dogs.


----------



## David Frost (Mar 29, 2006)

the handlers swear they never missed a giving a treatment. The medication had been purchased, according to both vet records and the bills we pay. The dogs had negative hw tests annually prior to the positive test. Current policy requires a physical annually, including a hw test. I track that through payment of the vet bills. All vet bills are paid out of my office. In both instances, prior to this warning about the dogs in West Tennessee, the company that made the preventative picked up part of the tab. 

DFrost


----------



## Maren Bell Jones (Jun 7, 2006)

At a clinic I was up at a few weeks ago, we had 3 dogs in one week come in heartworm positive. One ended up being fatal for the dog because of poor prognosis and monetary considerations, one did not yet have clinical signs, and one did (coughing, lethargy, weakness). The doctor had to call Merial and explain the clinical signs of the dogs and they made the decision of whether or not to send them the drug. Fortunately they OKed it for the dog with signs, so the dog got the treatment. We did an alternate protocol for the other dog without clinical signs to prep them for when the drug will hopefully be back.

Jerry, if you treat your own animal with a drug off label per manufacturer recommendations and they either have a reaction or die or come down with heartworm disease, the company is not liable for it when normally the companies will pay for the heartworm treatment if it happens (which is at least $500 around here).


----------



## Kristen Cabe (Mar 27, 2006)

I've had 3 HW+ dogs in the past 8 months. All came from Gaston County. I treated the first one with a homeopathic remedy, and he is due to be retested now. I need to get in touch with his new owner about that. The other two I got within a week of each other. One was _extremely_ high positive, and exhibited with coughing and nosebleeds shortly after being placed into a foster home. He had the nosebleeds off and on for two days. He is currently being treated with the same homeopathic treatment as the first dog, in addition to monthly ivermectin because his infection was so bad. The coughing and nosebleeds have since ceased. The other dog was only mildly affected, and is being treated only with monthly Heartgard. 

One reason I choose to use the homeopathic treatment is because of cost. I can't afford almost $800 a pop for conventional HW treatment (that is with a discount, btw). Another reason is because how extremely toxic the conventional treatment is, plus, there are some serious side effects in addition to what is considered 'the norm' for dogs to suffer through after each injection. On top of that is the fact that the dog must be kept on strict crate rest or the massive die-off of adult worms could kill him (and still could even on crate rest). I much prefer the slow kill methods. 

My own dogs are on heartworm nosodes for prevention, and that's it. I have them tested three times a year. If they ever test positive, I know it will be early on, and they will be treated homeopathically and/or with monthly ivermectin.



Maren, do you know anything about ivermectin being given more often than once-a-month for heartworm treatment? I've had people tell me that they were instructed to give it once-a-week, or even daily. I did not think that giving it more often worked any better than giving it once-a-month.


----------



## kim guidry (Jan 11, 2008)

Jerry Lyda said:


> David I use Ivomec for cattle and swine. I've had no HW issues. Lost is very low. I bought my bottle 3 yrs ago for $37.50. The cost is a little higher now, 40 something.


They use Ivomec at our training facility as well. It has served us well and it is cost effective for the amount of dogs we have. ( at any given time we have 15 to 35 dogs)


----------



## David Frost (Mar 29, 2006)

I was notified yesterday a dog I had trained for our Corrections Department, tested positive for heartworm. This dog has been in the program for over 4 years. It has had 3 negative test, during the annual physical, prior to the positive this month. They are retesting to the dog to make sure. According to the handler, the dog has been medicated monthly, without missing a dose. This dog is in the Western part of the state. I hope they get a handle on this, because it's some bad juju. All my handlers west of the river have been instructed to test semi-annually. 

DFrost


----------



## Candy Eggert (Oct 28, 2008)

David Frost said:


> I was notified yesterday a dog I had trained for our Corrections Department, tested positive for heartworm. This dog has been in the program for over 4 years. It has had 3 negative test, during the annual physical, prior to the positive this month. They are retesting to the dog to make sure. According to the handler, the dog has been medicated monthly, without missing a dose. This dog is in the Western part of the state. I hope they get a handle on this, because it's some bad juju. All my handlers west of the river have been instructed to test semi-annually.
> 
> DFrost


Good call David on the semi-annual testing. Ugly stuff that heartworm. Might get even worse with all the rains you've had down there too?!


----------



## Michelle Reusser (Mar 29, 2008)

Oh swell, Super Parvo, Fleas and Ticks not slowed down by Frontline+ and now heartworms laughing at Heartguard.


----------



## Debbie Skinner (Sep 11, 2008)

I just received an email last week from the owner of a 2 year Beauceron from me. She lives in Louisiana. Seems there's something up..resistance? quality control problem?
_
We had to put training on hold do to the fact that when we went for OFA ex-rays we were dealt a huge blow. "Dog's name" has heartworms. *He has been on heartguard all his life and never missed a pill. The vet said that there are about 27 other cases that he has heard of like his. *He has had the first round of treatment and is doing great. Although he has killed 2 heavy wire crates and hates having to be still. We start the last round of treatment on June 7th. *The vet was blow away when the blood work came back and showed possitive for heartworms. We get check-ups every 6mon and yearly blood work*. So we have caught it very early. But it took me over a week to be able to look at him and not cry. He has really stolen my heart. To look at him you would never know anything was wrong. He is beautiful and very outgoing. He stops people in their tracks when ever we go places. Even had the K-9 unit come see him on a training day. I still cant thank you enough for him and all your time answering all my questions. _


----------



## Denise Gatlin (Dec 28, 2009)

Debbie Skinner said:


> I just received an email last week from the owner of a 2 year Beauceron from me. She lives in Louisiana. Seems there's something up..resistance? quality control problem?
> 
> Louisiana is prevalent for HW disease as our climate and environmental conditions are so conducive on a year-round basis. With my own dogs, I have used liquid Ivermectin for nearly 20 years and my dogs all test negative regularly. Heartgard contains ivermectin, from what I am told. Our local LE K9 dept had all dogs come up positive for HW last year while on preventative. I also know of several in dog sport clubs whose dogs while on preventative have come up positive. Upon my questioning, it seems that the storage of their product has not been refrigerated. Not that that should make a difference I suppose, but I have always refrigerated my Ivermectin along with my other dog meds (the dogs have their own frig and med cabinet which concidentally is huge compared to our own . Also in the past, I have had nearly 200 rescue GSDs through here with only a handful who were negative at onset. Most went through the extensive treatment by vet, but due to the long-term risks (organ failure) as well as immediate death, I then chose to subscribe to the alternative method of titrating Ivermectin over a period of time. I have to say that I never lost a rescue since then and upon retesting, the dogs were negative. I have two still living with me and that has been since 2003.


----------



## Debbie Skinner (Sep 11, 2008)

Denise Gatlin said:


> Debbie Skinner said:
> 
> 
> > I just received an email last week from the owner of a 2 year Beauceron from me. She lives in Louisiana. Seems there's something up..resistance? quality control problem?
> ...


----------

