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Heartworm Prevention 2021 Update

Heartworm Prevention 2021 Update

Heartworms can be deadly and expensive to treat, but heartworm prevention is a decision that only YOU, the about-to-be fully informed dog owner, can make.

You are told that heartworm prevention is vital, safe, and effective. Consequently, millions of dog owners are making the decision to use the product without being informed of the odds of heartworm infection, the health risks involved, or that the treatment itself may not be as effective as expected in preventing heartworm infection.

Have you read the label on YOUR prescription medicine lately? Risk disclosure is required in human medication. How can your beloved dog, potentially worth thousands upon thousands in actual projections of puppies produced, be exempted from label lingo oversight and government mandated disclosure????

Oh wait, instead, there’s this legal “out” that relieves everyone but YOU of any responsibility for failure of a heartworm prevention “medication.” “Application of an Environmental Protection Agency (EPA) registered mosquito repellent/ectoparasiticide has been shown to increase the overall efficacy of a heartworm prevention program…” (Verbatim quote from multiple sources.)

In other words, everyone is exempted from liability for heartworm infection “damages” if the owner fails to use mosquito repellent.

But wait! There is no way an owner can legally prove that they administered the product. That is tantamount to saying the blowout that caused you to have a wreck isn’t the fault of the defective tire, it is your fault because your dog peed on your tire that day.

The American Heartworm Society admits to a “lack of efficacy” (LOE) in preventing heartworms.1 The term is accurate enough in that it is the FDA’s clinical definition of “a dog testing heartworm positive regardless of appropriateness (emphasis added) of dosage or administration consistency.”

Buried in long pages of fine print are statements such as: “There is also biological variation in how hosts within the same species metabolize a drug and host immune response to parasites, as well as how parasites respond to a drug. Thus, the cause of a reported LOE of a product can be extremely difficult
to determine.”

And sort of as an aside… “The increase in the number of LOE reports to the FDA during the past several years has led to concerns of possible heartworm resistance to the current heartworm preventives.” Oh, if in the remoted chance that a “lack of efficacy” fails to protect the manufacturer and distributor from legal liability, blame it on immune mosquitoes!

The American Heartworm Society goes on (and on) citing lab studies with high rates of prevention (not total success, but higher), but it then cautions veterinarians to make sure their clients understand the “implications of heartworm infection” and “the risk of heartworm infection in their area.” Good advice, especially since the heartworm-carrying mosquito has spread north, and “their area” may have moved from low risk to medium or high risk.

And then there’s this release-of-liability, cover-your-butt, sentence labeled as “critical” advice to ensure that clients are “providing their pets with appropriate year-round heartworm prevention.” I read that as: Buy their helpful (but explicitly NOT guaranteed product) year-round, even if you spend the winter covered in snowpack.

Most heartworm prevention products still recommend that “heartworm re-testing is conducted two to three times per year. This protects the dog from owner negligence or forgetfulness.

As a professional reporter, I know enough about marketing to be skeptical about “quantified advice.” However, you will decide whether to administer heartworm prevention year-round. But do so with the knowledge that it is, in fact, a systemic poison that can cause a myriad of seemingly unrelated health problems. Also, that it is explicitly NOT guaranteed to protect your dog. Most heartworm prevention products still recommend that “heartworm re-testing is conducted two to three times per year. This protects the dog from owner negligence or forgetfulness. We must assume that this is also meant to explain away and/or reveal any dog found to be heartworm positive while being treated with a preventative.

I am not “against” anything, including profit, but if the product works as represented (unless you read the fine print, some of which you have just been exposed to) then testing three times per year makes no sense. On the other hand, it makes perfect sense to veterinary practices in 2021, most of which are corporate entities, no longer owned by the veterinarian who just works for the company.

It is a good thing that I can re-use my hands, because then there’s this: Routine re-testing could decrease the risk of heartworm disease, but more to the point, it gets the dog in for, hopefully, what will be a through check-up. I would be remiss in not reminding readers that a dog that throws up the medicine is problematic. Your good vet is aware of that and, therefore, he or she may recommend YEAR-ROUND DOSING no matter where you live.

Minnesotans, listen up. This means that your pets get treated 365 days, without a break. In my opinion, the best thing about the report is that it may offset the decline in heartworm preventative sales.

Well, everyone will have to make their own decision. Many, like me, weighed the odds of (1) my dogs being bitten by a mosquito carrying heartworm larvae, (2) whether the larva ever make the long journey to the heart, and (3) the number of larvae actually mature so as to potentiate damage—as compared to the certainty of poisoning the dog every day. Re-read that slowly, and while you’re thinking about it, let me give you three definitive real-life reasons why Bill and I decided not to use heartworm preventative, even though we’ve lived
in Florida.

In the late 1960s, we managed a small racing Greyhound kennel for absentee owners. All the Greyhound kennels immediately ordered the new miracle styrid caracide that was/is a livestock wormer for cattle, sheep, etc.

Within six months, there wasn’t a racing kennel in the US that used it. Be it noted that (successful) racing Greyhound breeders and trainers are totally dedicated to canine care and diet, and they keep extensive health records. The first thing immediately noted was the “bottom line,” i.e., track times went off by as much as two seconds. Then, as bitches missed and litters failed to thrive normally, there was no doubt it was the new wormer. We heard there were lawsuits settled.

A few years passed and we were living in Orlando, next door to dog-friends whose property had a small, stagnant pond. Florida Crackers (the state got its nickname for the whips once so adroitly used to move cattle) called such ponds “mosquito factories.” Worried, we both decided to get our dogs tested. One of the Kearny’s four Dobermans tested positive for heartworm microfilaria, but she was seven years old and the vet treated her with a dose of styrid caracide. Bill and I had an older Doberman and two adult Rotties. All were negative. We played poker a lot back then and, after weighing the odds, the four of us decided that one out of seven was pretty good. Their beloved Tessa lived to age 13. None of our dogs “caught” heartworm.

A decade or so later, the marketing was even greater to put dogs on the preventative that, by then, could be given monthly. I asked my vet if we should use the “new stuff.” He thought for a full minute, then said that we had enough acreage, no close neighbors who might have infected dogs, and the odds were against my heavy-coated Akitas getting bitten on the nose or eyelid by a mosquito carrying heartworm. But, if we ever had a problem, he knew of a sheep wormer that would take care of it. It wasn’t “a big deal.” I still don’t use heartworm prevention and, knock wood, have never had a dog with heartworm… or allergies… or any immune system problems.

Heartworm prevention has saved millions of dogs from the disease. Oddly, I could find no statistics on the incidence among untreated dogs. Whatever, I’m going to guess that for every untreated healthy dog there is at least one dog on heartworm preventative that is NOT healthy. I say this because I started my own curiosity survey after observing the parade of obese, hairless, itching, allergic, SICK dogs during a two-hour wait in the vet’s office. I say it because very few of my puppy owners poison their dogs, and I have never—in forty years—had one single owner tell me their dog had heartworm.

I don’t recommend anything to anyone. I just thought you
might like to know some of the risks, so that you can make your own informed decisions.

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