You need to be careful when choosing which heartworm prevention medication that you give your dog, given the seriousness of a heartworm infestation.

Proheart Six, first available in 2001, is a medication administered as one injection once every six months. This was originally seen as a safe & simple way to provide heartworm prevention every six months. However it peaked the FDA's attention after more than 5,000 reports were filed detailing poor reactions, which included 415 deaths.

The FDA investigated and figures show the number of deaths per year caused by adverse reactions to ProHeart 6 were much higher than monthly heartworm medications. On average of 138 deaths a year compared with as few as 6 for Heartgard heartworm protection and Sentinel. (Source FDA: As of 05/03/2004)

Without wanting to scare any pet owners out there, it's wise to remind people that giving any kind of dogs heartworm control can cause allergic reactions. In the worst case scenario, they might result in the death of your pet.

According to the FDA (2004), Revolution heartworm protection had reports of an average of 36 annual deaths from over 8,500 reactions. Keep in mind however, that the statistics read higher than Proheart 6, simply because the product has been on the market much longer and has been administered to many more pets. Proheart 6 has actually caused more than three times as many deaths.

Although these statistics can seem scary, you should remember that Revolution is used as a popular flea and heartworm prevention by many in which most all benefit greatly from it. Also available is Interceptor for your dog. It has been reported of having around 214 adverse reactions, which is eight times less than the flea and heartworm control of Revolution. Interceptor averages 9 deaths per year as opposed to the average 138 deaths per year from Proheart Six.

From 1995 to 2004, Interceptor heart worm protection was reported to have a mere 84 deaths throughout the entire 9 years. Reported during that time, Heartgard averaged 6 deaths from 355 adverse reactions. Heartgard chewables contain ivermectin as a heartworm protection.

The parasite, flea and heartworm medication with the fewest adverse reactions and deaths is Sentinel. From 1999 to 2004, fewer than 900 adverse reactions were caused by this heartworm prevention treatment for dogs, averaging 233 per year in comparison with 1737 reactions caused by Revolution heartworm treatment, and the total number of deaths reported was 25, or an average of 6 per year.

ProHeart 6 should only be used for preventative heartworm control, and should not be used if heartworms have already become established. Monthly heartworm prevention and treatment is a popular choice, but numerous vets maintain that Proheart is safe. In 2007 Proheart 6 was still on the market as a heartworm prevention medicine despite the fact that it was recalled in September 2004.

Of course you want what is best for your pet as it is a family member, not a statistical reading, however these adverse reactions in which you have been informed of are from millions of dogs throughout the world and are considerably low. If you are concerned about your pets health, choosing prevention is the best action for you. Discuss your options with your vet and ask all the questions in which you deem necessary.

Please do not underestimate the devastating effect of heartworms in dogs. By choosing an easy to administer monthly dose of heartworm preventive medicine, you can spare your pet a lot of hardship.