[megansmomma]

Heartworm Preventive Medication in Dogs: The Debate
by LORIE HUSTON, DVM on JULY 28, 2010

Recently, I came across an article about the use of heartworm preventive medications in dogs written by Dr. Karen Becker. Dr. Becker opens by quoting an article that I wrote for Examiner.com about the currently recommended methods of heartworm prevention in dogs and asks in the title of her article why I did not share various “facts” with my pet-owning readers.

Quite simply, and with all due respect to Dr. Becker’s opinion, I did not inform my readers of these “facts” because I do not believe them to be true.

Further, I believe that advising people not to administer heartworm preventive medications to their dogs when they live in endemic areas places their dogs at risk needlessly. And, to be quite clear here, we are talking about the risk of death. Heartworms can be a fatal condition!

Conspiracy Between the American Heartworm Society and Pharmaceutical Companies?

Dr. Becker implies that there is a conspiracy between the American Heartworm Society (AHS), an organization that recommends heartworm prevention for all pets, and the major pharmaceutical companies. In my opinion, this is stretching the truth a bit. Is the AHS sponsored by pharmaceutical companies. Probably. Does that mean that their recommendations are not based in science? No. What it means is that the AHS has examined the issue thoroughly (based on the known science) and made appropriate recommendations to provide adequate protection for your dog. It also means that the pharmaceutical companies have realized that helping the AHS educate veterinarians and pet owners about the fact that this protection is necessary helps sell their products. However, it does not invalidate those recommendations.

Are Heartworm Infections in Dogs Uncommon and Not Usually Lethal?

Dr. Becker says “Heartworm disease is more difficult to acquire – and less lethal – than the dire warnings and marketing claims for chemical preventives would have you believe.” This has not been my experience. I’ve diagnosed heartworm disease in more dogs than I care to count and some of them did not survive the infection. Others were critically ill as a result of the infection, making treatment for the disease much more difficult and dangerous.

My experience is shared by April Ellis Mitchem, the Birmingham Dog Care Examiner at Examiner.com and long-time rescue worker, who says “We take in enough heartworm positive dogs with rescue that I completely disagree with the assessment that it’s hard to acquire.”

April’s assessment is shared by Karen Wood Philhower, who runs a Beagle rescue group. Karen says, “We get A LOT of heartworm positive dogs and not just from the South, though it’s all too common there. I’ve had dogs from New Jersey that were infected as well. I also disagree with Dr. Becker’s statements and I am alarmed that a practicing veterinarian would potentially jeopardize the health of pets by following this advice. Heartworm preventatives have been around a long time and when given at the proper intervals and in the correct dosage they are very safe and effective. I give monthly ivermectin/pyrantel to my own dogs as well as foster dogs year-round. I’ve lost foster dogs to advanced stage HW disease and it angers me because it is so preventable. Treatment is expensive and hard on the dogs, even under the best of circumstances.”

In my experience, April and Karen are absolutely correct. Heartworm disease is seen frequently in the south and often enough in colder climates that not administering heartworm preventive medication, in my opinion, is irresponsible and risky.

Are There Less Toxic Alternatives to Monthly Heartworm Preventive Medicines?

In my opinion and experience, the monthly heartworm preventive medications are both effective and quite safe. I have serious doubts about whether Dr. Becker’s recommendations are sufficient to prevent heartworms, especially in endemic areas with high risk of exposure.

While I respect Dr. Becker both as a colleague and as a person, I believe that she is somewhat misguided in these recommendations for heartworm control. My fear is that her recommendations will cause pet owners to forego administering heartworm medications to their dogs, thereby unknowingly exposing their pets to unneeded risk.