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The Nature of Animal Healing

by Dr. Martin Goldstein


To judge by your local veterinarian's stern insistence on regular heartworm  pills for your dog, you'd think we're in the midst of a brutal epidemic, leaving piles of the dead in its wake. I think there's an epidemic, too, but of a different sort: of disease-causing toxicity instilled in our pets by heartworm preventative pills.


Granted, heartworm is a serious condition. An infected mosquito bites your dog (cats are rarely affected), injecting microscopic worms that first hibernate, then gain access to his bloodstream. The worms find their way to the heart, where they grow to as long as twelve inches, constricting the heart's passages and causing symptoms that range form coughing to labored breathing to hart failure. If the image of giant worms literally blocking the life blood of your dog isn't horrifying enough--and it can seem more so when viewing a real heart preserved in a jar of formalin, on display in a veterinarian's office as a sales tactic for heartworm preventative--the fact that they spawn hundreds of thousands of baby larvae, called "microfilaria," which circulate through the bloodstream, is nothing short of grotesque.


A few caveats are in order, however. Only a small percentage of dogs who get heartworm die of it, especially if they're routinely tested twice yearly for early detection. Even in untreated dogs, after a period of uncomfortable symptoms, the adult worms die. The microfilaria do not grow into adult worms on their own. To reach the next stage in their life cycle, they have to be sucked back out of the body by another mosquito, and go through the other stages of their maturation process within the mosquito.  Only when that mosquito alights again on a dog and bites it can the microfilaria reenter the bloodstream with the ability to grow into adults.  The chances of a microfilaria-infected mosquito biting your dog the first time are slim. Of it happening to the same dog twice Very slim. And after two decades of pervasive administration of heartworm pills in the U.S., the chances of your dog contracting heartworm in most parts of this country even a first time are slimmer still. Early in my career, I saw and treated hundreds of cases of heartworm disease, most with routine medication, yet witnessed only three deaths (the last was in 1979). By comparison, we're seeing cancer kill dogs on a daily basis. To my mind, the likelihood that toxicity from heartworm pills is contributing to the tremendous amount of immune suppression now occurring, especially in cases of liver disease and cancer, is far greater and more immediate than the threat of the disease they're meant to prevent.


The most common form of heartworm prevention is a monthly pill taken just before and during mosquito season. (Many veterinarians recommend giving it year-round, even in areas of the country that experience winter.) Its toxins--ivermectin, for example--sweep through the body, killing any microfilaria that have been introduced by mosquito bites in the previous month, and thus preventing the growth of adult worms. Some brands also contain other toxins to kill intestinal parasites. The other approach to treatment is with a daily dose of the drug diethylcarbamazine, starting several weeks before mosquito season. The drugs called for in either course of treatment are, simply put, poisons. Unfortunately, while they kill off microfilaria, they have the toxic effects of poisons, and can be especially damaging to the liver. I've saved a 1987 product evaluation for diethylcarbamazine mixed with oxibendazole, a preventative also used for hookworm. The evaluation, published by the company itself in a medical journal, reported that of 2.5 million dogs give the stuff, the company received only 176 reports of problems. Including cases of liver toxicity and fatalities. To me, 176 is too many. But also, how many more went magnitude of occurrence is really unknown." The manufacturer would argue, no doubt, that many of the symptoms I've seen cannot be linked in any provable way to any of the heartworm preventatives. Perhaps - though the anecdotal evidence has long since persuaded me not to put dogs on the stuff. But I have seen one obvious, immediate effect of these once-a-month preventatives in case after case: when you give a dog that pill, over the next few days, wherever he urinates outside, his urine burns the grass. Permanently! In some cases, you can't grow grass there until you change the soil. What, I wonder, can it be doing internally to your dog in that time?


When the first daily preventatives came out, my brother and I witnessed evidence of hemorrhaging in the urine of several dogs put on them. We stopped the medication; the bleeding stopped. We started it up again; the bleeding resumed. When we reported this to the manufacturer, we were informed that the company was aware of the problem from other complaints.  Aware--but not about to pull its product form the shelves. All we could do was to stop giving the medication ourselves to the dogs we treated. Since then, the company has changed the product, diminishing this side effect and bringing it into the realm of acceptability for use in areas of high heartworm incidence.


The dogs I treat from puppyhood receive no heartworm preventative pills. It may be said, of course, that I practice in an area where cases of heartworm are pretty infrequent. But while my clinic is in Westchester County, just north of New York City, my practice encompasses patients from around the country. In the last decade, 98 percent of my patients, on my recommendation, have not been given heartworm preventative. In that time, I've seen less than a handful of clinical cases. Two of them I treated herbally, starting with heart support supplements (a heart glandular, vitamin E, Co-Enzyme Q IO) and regular doses of black walnut, an herb known to kill parasites. (It comes in a liquid extract form; I recommend putting a dropperful in the food or mouth at each meal.) The third I treated medically, with a new drug (Immiticide) reported to be a lot less toxic than intravenous arsenic, at a lower-than-recommended dosage. All three are clinically normal--no evidence of heartworm recurrence--years after treatment.


As a precaution, I recommend that all dogs be tested twice a year for heartworm. For clients who insist on a more active form of prevention, I suggest doses of black walnut given two to three times a week, as I've actually reversed clinical heartworm with it. (For a thirty-pound dog, one capsule three times weekly during mosquito season in areas that have reported any incidence of heartworm.) We also use a homeopathic nosode.  In areas where the chances of heartworm exposure appear greater than those in my own--like southern Florida and the Bahamas, where the chances of contracting it are high--I recommend adding to this regimen the conventional daily heartworm pill, given three times weekly. Veterinarians trained in homeopathy can get your pet on a good nosode program for heartworm prevention.


Excerpted from The Nature of Animal Healing by Martin Goldstein Copyright©

2000 by Martin Goldstein.


Dr. Martin Goldstein earned his B.S. and D.V.M. from Cornell University. He has written numerous articles about holistic veterinary medicine and alternative therapies for many magazines, journals and related publications. He has many happy and healthy dogs and cats, all of which areliving proof of the philosophy contained in his book, The Nature of Animal Healing.


Dr. Martin Goldstein:

Dr. Martin Goldstein's Smith Ridge Veterinary Center is in South Salem, New York.  He received his D.V.M. from the Cornell University College of VeterinaryMedicine.


He has many cats and dogs, all of which are quite old and healthy.


Buy these Books:

The Nature of Animal Healing

The Definitive Holistic Medicine

Guide to Caring for Your Dog and Cat

by Martin Goldstein D.V.M.








Heartworm Protect Herbal Formula


Heartworms have been found in animals worldwide, and in all 50 US States, posing a risk to all of our beloved pets. Because heartworms are transmitted by mosquitoes, it is important to consider the climate, the length and severity of "mosquito season," and the rate of heartworm incidence in your area when planning the best heartworm prevention plan for your pet. A good holistic veterinarian can help you determine what an appropriate heartworm prevention plan should include for your pet, and what role a natural herbal preventative like our HW Protect can play in helping to prevent heartworm disease in your companion.


HW Protect Herbal Formula offers an herbal alternative to the chemical heartworm prevention methods available, without the degree of side effects that have been documented with their use. Chemical heartworm preventatives work by continual administration of a low dose of insecticide to kill any developing microfilariae (microscopic sized baby worms). Herbal preventatives work in a similar fashion, using herbs instead of pesticides. NEITHER method kills adult heartworms, so regular testing for heartworm, at least every 6 months, is absolutely necessary regardless of what method you choose for prevention.


HW Protect Herbal Formula is intended for use as a preventative to be used during mosquito season as part of a comprehensive heartworm control program. The formula was designed with two objectives, using herbs that work together to reduce the likelihood of mosquito bites to lower your pet's risk of becoming infected, and to help eliminate existing larvae-stage parasites in the bloodstream. This tincture was developed to help prevent heartworm infestation using extracts of herbs well known for their mosquito repelling properties, and others well known for their anti-parasitic properties.


Heartworm disease (adult heartworm infestation in the heart and lungs) is a very serious health concern and treatment for heartworm disease should ALWAYS be guided by a veterinarian. If your pet already has heartworms, then we would suggest the Para-Gone Herbal Formula. If your pet has heartworm disease, then you should consult a veterinarian and follow a traditional heartworm disease treatment program, as elimination of heartworm can be complicated and carries additional risks to an animal's health.


Using insect repellents like those in Holistic Dog Flea and Tick Shampoo & Conditioner may also help prevent heartworms by keeping mosquitoes away from pets when they are outside.


As with all herbal remedies and treatments, the healthier the animal is overall, the more effective the treatment will be. Providing your companion with the best diet along with proper health-supportive products for optimal health will go a long way to preventing disease and making them less appealing and susceptible to parasites. Please see our articles, What You Need to Know About Your Pet’s Food, and Daily Supplements for Your Companion for more information.


For additional information on heartworm and parasite infections, you will find our articles, Intestinal Worms and Heartworm, and Natural Worm Control, available in our Holistic Healthcare Library, or consult a holistic pet care reference book, such as Herbs for Pets, Dr. Pitcairn's Complete Guide to Natural Health for Dogs & Cats, or The Encyclopedia of Natural Pet Care.


Herbs and Properties for Which They Were Selected

  • Wormwood Aerial Parts (Artemisia absinthium) - May help eliminate microfilaria and developmental stage heartworm parasites and in the bloodstream, and may help create an unfavorable environment for parasites.

  • Papaya Leaf (Carica papaya) - Contains enzymes (papain) that may digest parasite worms in the intestines.

  • Epazote / Wormseed Aerial Parts(Chenopodium anthelminticum) - Well known as an anti-parasite herb.

  • Male Fern Root (Aspidium filix mas) - May be effective in helping to control blood parasites.

  • Black Walnut Leaves (Juglans nigra) - May help support the body's defenses against parasites and help eliminate larvae stage parasites. It is also popular for its cleansing properties.

  • Ginger Root (Zingiber officinalis) - May work against blood flukes and may help relieve inflammation.

  • Oat Seed (Avena sativa) - A source of vegetable fiber.

  • Parsley Root (Petroselium crispum) - May help to remove waste materials and act as an insect repellent.



Heartworm | Blue Rose Cavalier King Charles Spaniels | United States

FDA Approves Potentially Deadly ProHeart 12


By: Julia Henriques

Reading Time: 7 minutes

The FDA just announced the approval of a ProHeart 12, a brand new heartworm preventive for dogs. 

Yippee! New must mean better, right?  

Well … no. 

The FDA thinks this drug is safe to use on your dog. But frankly … we’re baffled that they’ve approved it. 

And so are several holistic veterinarians. Scroll down to read their comments.  

ProHeart 12 is made by Zoetis, Inc. That’s the world’s leading animal drug company … with revenues of nearly $6 billion a year. 


HWF (formerly Heartworm Free) naturally supports the heart and circulatory system for a safe and healthy summer.

What Is ProHeart 12?

It’s an extended release injectable drug designed to prevent heartworm in dogs for 12 months. It also prevents and treats hookworm infections.

But before you think “oh, that’s super-convenient – I’ll ask my vet about it” … 

Hold your horses!


You need to know more about it before you run to your vet for a prescription. 

This drug is a stronger version of ProHeart 6. That’s a drug that came out in 2000, offering 6 months’ heartworm prevention.


But it was taken off the market in 2004 after many reports of adverse events (including deaths). 

RELATED: The Risks Of Heartworm Drugs

Since ProHeart 12 is new, there’s not much information about its specific side effects yet. 

But it uses moxidectin … the same active ingredient as ProHeart 6 … and in a higher dose. 

So let’s look at the history of that drug.  

ProHeart 6 Adverse Reactions

It’s no wonder they had to withdraw ProHeart 6 from the market. 

The FDA received more than 5,500 reports of severe adverse reactions in a 4-year period. These included more than 600 deaths.  Other side effects were:

  • Anaphylaxis (severe allergic reaction)

  • Seizures

  • Elevated liver enzymes

  • Immune-related blood problems

  • Cardiovascular disease

  • Mast cell tumors 

  • Lymphosarcomas

  • Histiocytomas

And it gets even worse.  

The FDA Doctor who realized the dangers of ProHeart 6 was taken off the case and criminally prosecuted. 

Scandals abound with this drug! 

ProHeart came back in 2008. 

And when that happened, a Congressional committee wrote to the FDA asking them to explain their findings related to the product’s safety. 

(Read the letter here…)

ProHeart 6 Relaunch

The FDA at that time decided to allow ProHeart 6 back on the market. 

The manufacturer, Fort Dodge Animal Health (later bought by Zoetis), worked on a Risk Minimization Action Plan (RiskMAP).

They agreed to implement a few safety measures:

  • Restricting the drug to veterinarians trained and certified in its use

  • Requiring informed consent by dog owners before treatment

  • Adding more safety and risk information to the product label

  • Setting criteria for dogs to qualify for treatment 

  • Eliminating residual solvents in the product that may have contributed to the adverse effects


The FDA says that when ProHeart 6 returned to the market, reports of death from the product decreased. 

But … when you look at that list of safety measures, there’s only one item that changes the product … and that’s removing the residual solvents!


So the rest of their safety plan was just educating vets and dog owners … to be more cautious about using it.

Meanwhile, in Canada, the ProHeart 6 label stated that the drug should only be used in dogs who couldn’t have other heartworm preventives:

“Because Of Its Potential For Serious Adverse Drug Reactions And The Absence Of Identifiable Risk Factors Associated With Those Reactions, ProHeart 6 Is Only Indicated For Those Dogs In Which Alternative Preventatives Cannot Be Effectively Administered.”

So with that background, the FDA has now approved ProHeart 12. And we can’t help wondering why.

And Now … ProHeart 12

Here’s what’s especially shocking. This new product, ProHeart 12, is almost the same as ProHeart 6. But it contains three times the concentration of moxidectin.

So let me ask this? 

If ProHeart 6 isn’t safe … why would you want to inject your dog with ProHeart 12 … that has three times as much of the active ingredient, moxidectin? 

And, like other heartworm drugs … it’s not really a preventative. It doesn’t prevent anything. Because it works by paralyzing and killing the worms … once your dog already has them. 

And what if your dog has an adverse reaction? 

The drug is already in your dog … for 12 months (or probably longer).  You can’t just stop using it once it’s injected. 

What’s Moxidectin?

The active ingredient, moxidectin, is used in tablet form to treat onchocerciasis (river blindness) in humans. The label for that drug says the drug doesn’t kill the adult worms that cause the disease … Onchocerca volvulus. It just stops them from releasing microfilariae. It also says “the safety and efficacy of repeat administration of Moxidectin Tablets in patients with O. volvulus has not been studied.” 

Zoetis knows moxidectin can be harmful to dogs. 

The product label for ProHeart 12 cites an alarmingly long list of adverse events of ProHeart 6. 

(And, in case you missed it … there’s 3 times as much moxidectin in ProHeart 12 as Proheart 6 … so side effects are likely to be greater.)

This is the exact list of adverse events on the label …

Immune: anaphylaxis and/or anaphylactoid reactions, urticaria, head/facial edema, pruritus, pale mucous membranes, collapse, cardiovascular shock, erythema, immune-mediated hemolytic anemia, immune-mediated thrombocytopenia (signs reflected in other system categories could be related to allergic reactions, i.e. gastrointestinal, dermatologic and hematologic) 

Gastrointestinal: vomiting (with or without blood), diarrhea with or without blood, hypersalivation

General: depression, lethargy, anorexia, fever, weight loss, weakness

Dermatological: injection site pruritus/swelling, erythema multiforme

Neurological: seizures, ataxia, trembling, hind limb paresis 

Hematological: leukocytosis, anemia, thrombocytopenia

Respiratory: dyspnea, tachypnea, coughing

Hepatic: elevated liver enzymes, hypoproteinemia, hyperbilirubinemia, hepatopathy 

Urinary: elevated BUN, elevated creatinine, hematuria, polydipsia, polyuria and
cardiopulmonary signs such as coughing and dyspnea may occur in heartworm-positive dogs

In some cases, death has been reported as an outcome of the adverse events listed above. 

Even if you’re really scared of your dog getting heartworm … do you really want to trade the risk of heartworm for that frighteningly long list of serious side effects?

Let’s talk about the reaction from some holistic vets who understand the risks. 

What Veterinarians Are Saying


We’ve already seen some horrified reactions from holistic vets we know:

Josie Beug DVM said:

“I cannot believe this was approved. When Fort Dodge originally made ProHeart 6 we were seeing auto-immune hemolytic anemia cases from it: the dogs’ immune systems began destroying their own red blood cells. I saw several cases myself. The product was taken off the market. 

Please do not allow your veterinarian to inject your dog with this!”

Judy Morgan DVM commented:

“I cannot believe this got approved. Dogs died with the 6 month injection, resulting in it being pulled from the market. It was then re-released with no changes. If the six month concentration was dangerous, why in the world would they make it three times more concentrated????? This infuriates me!!

Patricia Jordan DVM reminded us:

“When ProHeart 6 was pulled and then reintroduced, Canada said it was the heartworm prevention of last resort.

“When it was reintroduced, all the doctors had to go through a webinar before they could prescribe it. They taught the product was not to be given anywhere around vaccines. Even the FDA found ProHeart 6 caused cancer.

“The FDA Vet that pulled ProHeart 6 said that the company was aware of the risk of cancer. She said there were more adverse events with just ProHeart than every one of the heartworm preventions put together.” 

But not all vets will tell you this …


HWF (formerly Heartworm Free) naturally supports the heart and circulatory system for a safe and healthy summer.

Not All Vets Know This

Your vet may try to talk you into this drug. Especially if she thinks you’re forgetful. Check out this Facebook post by one North Carolina clinic …

Foothills Animal Clinic writes:

“FINALLY! 12 months of heartworm prevention in one injection.”

And here are several clinics promoting ProHeart 6:

Horseshoe Lake Animal Hospital, Resort & Salon writes:

“…the introduction of Proheart! Proheart is an INJECTABLE heartworm prevention that is only given every 6 months! …”


Racine Veterinary Hospital writes:

“Proheart 6 is an injectable heartworm prevention. 1 injection lasts 6 months, which means you don’t have to worry about missing a dose…”


Eastpoint Vet writes:

“Proheart injections are going well this month … [it] lasts 6 months! You can’t get any easier than that! …”


…because you don’t have to remember to give your dog a pill every month. How great is that?  Ugh. 

So who should you listen to … the holistic vets who warn against Proheart 12 or the ones who want your dog to take it?

Only one vet gets paid when you give your dog Proheart 12 …

So the answer is, don’t let any vet use this drug on your dog. For any reason.

There are lots of safer ways to prevent heartworm.

RELATED: Why I Don’t Give My Dogs Heartworm Meds (And Why You Shouldn’t Either)

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