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.
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.
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 …
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)
