Heartworm Protection: Do We Need ProHeart 6?
Written by Jan on June 18, 2008 – 11:06 amProHeart 6, a heartworm “preventative” shot providing 6 months of protection against canine heartworms, is back on the market after having been pulled from shelves in 2004 by manufacturer Fort Dodge. More than 5,000 adverse “events,” including hundreds of canine deaths, prompted the FDA to request the drug’s withdrawal. It is being brought back under a “risk minimization action plan” and restricted use program (including vet training and informed consent notification) — an uncommon plan to try to limit damage from the drug.
I wonder, why is ProHeart 6 so indispensable that it must be brought back? There are safer once-a-month heartworm “preventatives.” More importantly, there are countless natural, non-toxic alternatives. (By the way, heartworm drugs do not “prevent” heartworms. They kill them.)
Does a risky six-month remedy have any real value? Not to me as loving guardian to two dogs, and certainly not to the dogs themselves who may suffer potentially lethal adverse reactions. The main value will be to Fort Dodge stockholders and to the vets who benefit from the sale of the product plus the office visit to give the shot.
Before writing about heartworms and other parasites for my book, Scared Poopless: The Straight Scoop on Dog Care, I interviewed three veterinarian-authors and two other holistic vets, and also spent months reading and doing on-line research. Every vet I consulted thought heartworm medications were toxic. Dr. Martin Goldstein, renowned veterinary and author, has written that he sees heartworms as less of an epidemic than the “disease-causing toxicity” of heartworm medicine.
No discussion of this medicine would be complete without a study of the heartworm life cycle. Microfilariae, which grow into heartworms, must be injected into dogs by female mosquitoes. No mosquitoes, no heartworm infestation. Dogs with poor diets, and those suffering from immune system dysfunction, are particularly susceptible.
Most U.S. locales don’t have mosquitoes in cold weather. But even if mosquitoes are present, according to the University of Pennsylvania vet school, microfilariae require sustained periods of weather above 80 degrees and not below 57 degrees (Fahrenheit) to develop to the proper stage to be delivered.
Thus, protection against heartworms is unnecessary year round in many locations. Read more about the mosquito’s life cycle at a website owned by ProHeart manufacturer Fort Dodge, click here. For an unbiased look at nationwide incidences of heartworm and drug adverse reactions, click www.dogsadversereactions.com/moxidectin/heartwormmaps.html
I live in Southern California, an arid area with few heartworm cases. For my own dogs, I use non-toxic alternatives: natural non-toxic bug repellent and keeping the dogs indoors when mosquitoes are buzzing. I also make sure there is no standing water in my yard.
I increase safety by testing my dog’s blood once yearly for heartworm antigens, something also required if they were to take heartworm “preventatives.” If I lived in an area with sustained hot weather and lots of mosquitoes, I’d test twice yearly. Heartworm infestation is generally curable when caught early. The current canine movie star “Benji” is a heartworm survivor.
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A follow-up: Still considering giving your dog ProHeart 6 for heartworm protection? ProHearts’ own Client Information Form lists adverse reactions: “These can include (but are not limited to) allergic responses, lethargy (sluggishness), seizures, vomiting and diarrhea, itching at the injection site, fever and, in rare instances, death.” Read the entire Proheart form at (Note: To enlarge the print size, change it to “100%” on the toolbar underneath the word “Help.”)
An article from the FDA worth reading reports “the side effects…anorexia (loss of appetite); lethargy; vomiting; neurologic signs, such as seizures, difficulty walking and reports of blindness; jaundice (a yellowish appearance); and bleeding disorders. Most of these observable clinical signs have occurred within one month of receiving the drug.” www.fda.gov/cvm/PH6QA.htm
To comply with the FDA’s “risk minimization” plan, Fort Dodge is implementing an educational and communication program that will require veterinarians to register with Fort Dodge and complete “in-depth” training as a condition of purchasing ProHeart 6. A letter from the FDA explains vets will also have to “confirm they have completed the in-depth training, read the new label, the conditions of use, the requirements to provide the dog owner with the Client Information Sheet and obtain signed informed consent, record the product lot number in the medical record, and report adverse events. Veterinarians are also advised to obtain baseline history, physical exam, and blood-work parameters prior to administration of the drug to confirm the patient is an appropriate candidate for ProHeart 6.” Read the entire letter at http://www.fda.gov/cvm/ProHeart6AVMA.htm
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Posted under Heartworms, Pet Meds, Uncategorized | 6 Comments » Email This Post

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March 6th, 2009 at 10:03 am
[...] Dangers Written by Jan on March 5, 2009 – 5:46 pm This is a follow-up to our first article on Proheart 6. You might want to read it [...]
March 24th, 2009 at 5:53 pm
So, you would recommend a heartworm test yearly? Would you give heartguard or not? I live in San Diego. How would I find a good holistic vet? Any recommendations?
Thanks a bunch!
Pam, Isabelle (husky mix), & bandit (border collie)
June 3rd, 2009 at 11:34 pm
Well said. Thank you so much for this article.
My dogs were early victims of this poisonous pet product. You can read Tasha, Niki, and Casey’s story under “ProHeart 6 Victims” at http://www.thepetguardian.com.
The FDA allowed Fort Dodge to back-door this product back onto the market without allowing us, the public, a “voice.” Thank God the U.S. dogs were safe for almost four years while it was off the market.
The pet-loving public should know: If you get this heartworm “prevention” shot for your dog, you are having literally a pesticide injected into them. Would you do that to yourself or your human baby??
Within 24 hours, this drug has permeated all organs of the dog’s body. If the dog reacts adversely, there is NOTHING that can be done to remove the drug from his body. The dog is forced to suffer the effects for as long as it’s in his body — if he can live that long. And since the drug is time-released, every month about the time the injection was given, he may suffer those adverse effects again.
I’m not saying not to give heartworm “prevention” — if you have to in your state — but don’t go the injection route, no matter who the manufacturer may be.
I cannot emphasize strongly enough: YOU are the expert when it comes to your companion animals, not your vet — and certainly not a drug manufacturer who cares very little about you or your animals. They’re in the business of making money, period.
BUYER BEWARE! Be safe, not sorry!
June 4th, 2009 at 1:08 pm
Jean, I’m glad you liked the article and applaud your advocacy for dogs. I’m so sorry that you, like so many of us, had to learn the truth about pet medications hard way.
Did you read my recent articles on Heartworms Medications and Pesticide Poisoning? Flea and tick meds are a big problem, too. My newsletter just went out and Heartworms are the first major subject. I’m writing Part 2 of Heartworms to go out soon. I hope you’ve subscribed to this blog so you’ll be notified. Maybe you’ll come back and comment again. Perhaps you’ll also bookmark heartworm articles at Delicious, StumbleUpon or other networking sites. There’s a link on this page. Let’s spread the word!
Thanks again. And keep up the great advocacy.
June 11th, 2009 at 6:52 pm
Thank you, Jan. Like you, I cannot sit by and watch our animal companions be harmed and die at the hands of these “harmaceutical” companies.
I have not seen your recent newsletter. Can you please add me to your list for all your mailings? I am going to subscribe by RSS, but truthfully, I’m not sure where these things are going.
But I would definitely like to be kept in the loop. I started up my Pet Guardian blog again. Between the two of us — and others, I am sure — we can spread the word even further.
Thank you so very much for all you’re doing for the animals!
October 19th, 2009 at 6:03 am
I started giving my dog black walnut in his food and it gets rid of over 100 different parasites including heartworms. He was positive for heartworms before I gave black walnut to him and black walnut got rid of the worms.