Beware of ProHeart 6

ProHeart 6 is an injection for dogs that prevents heartworm for 6 months.  Its primary ingredient is moxidectin.  This product was originally approved by the FDA in 2001.  Nearly 6,000 adverse reactions were reported in dogs following the administration of the drug over a three-year period, and sadly over 600 dogs died.  It was recalled by the manufacturer at the FDA's request in 2004.

The first time I heard of ProHeart 6 was when my vet recommended it for my Rottweiler Katie in Orlando, Florida in 2002.  Unfortunately, I was not informed of possible adverse reactions, and I allowed her to be injected with the drug.

Within an hour of the administration after we returned home, Katie was lethargic, began vomiting and was unsteady on her feet.  I called the vet and was told to bring her back immediately.  She was treated for the reaction and fortunately was okay.  It was later that year that I began hearing about ever-increasing safety concerns about ProHeart 6.

Surprisingly, the FDA announced the ‘limited reintroduction’ of ProHeart 6 in June 2008. 

But get this...

1.  Proheart 6 is the first veterinary drug to be marketed under a risk minimization and restricted distribution program. 

2.  The drug can only be administered by veterinarians who take a course and are certified by the manufacturer.  

3.  It should not be administered within one month of vaccinations. 

4.  It must be used ‘with caution’ in dogs who have had allergic conditions, and should not be given to dogs that are sick, underweight or debilitated. 

5.  An owner must be advised of the risks of ProHeart 6 AND sign a consent form prior to its administration. 

I don’t know about you, but that sure seems to me like a whole lot of CYA by both the FDA and Pfizer Animal Health.

I found this video in which a veterinarian expresses his concerns and recommendation regarding ProHeart 6.

I appreciate Dr. Pinney’s candor, and hope that his conservative approach to this drug is echoed throughout the veterinary community.

My personal recommendation is to stick with heartworm preventatives for your dogs that have been on the market for many years and are widely considered safer.  Most dogs happily chow down their monthly heartworm preventative like a treat, and the amount of time that takes each month (15 seconds?) is a lot less time than having to take your dog to the vet every six months for an injection.

Please share this information with your dog-loving friends, family and co-workers!  Already, new concerns are being raised about this questionable drug.  Hopefully the ‘reintroduction’ of ProHeart 6 won’t cause the suffering and pain in dogs and their humans that it did when it was first put on the market.