Canine Heartworm

 By: Michael Lamping, DVM

            The heartworm parasite primarily affects dogs, but cats and ferrets can also acquire life-threatening infestations.  The worms inhabit a dog's heart and the blood vessels of the lungs.  Dogs with symptoms of heartworm disease typically cough, become fatigued at playtime, and fail to thrive.  Severe cases may develop congestive heart failure, kidney disease, and liver failure.  Heartworms can grow up to 12 inches long and can accumulate to infestations in the hundreds.

Mosquitoes are responsible for transmission of the parasite from one dog to the next.  You may think of heartworm disease then as an illness of concern only in the summer months when mosquito populations are most abundant and active, yet February is a month when we can see snow on Valentine's and air-conditioning on Presidents' Day.  A few days of warm weather is all it takes to start seeing mosquitoes again.  In addition, this moist winter may continue into spring and though it is long overdue, healthy rainfall totals bring the undesired consequence of increased mosquito populations.

             Heartworms are present in all 50 states, and we certainly see it in our area.  The veterinarians at Murphy Road Animal Hospital diagnosed heartworm, on average, every other week in 2006. 

            Veterinarians can treat dogs with infections but treatment is not without risk.  Hospitalization is required, the medication is costly, and fatal adverse effects can occur.  Fortunately, we can protect dogs from heartworm disease by prescribing a safe and affordable once-monthly preventative.

            If you are not keeping your dog on a preventative you are playing Russian roulette with each mosquito bite.  There are no "immune breeds" and dogs are not protected by long coats or thicker skin.  Therefore I recommend that all dogs receive annual blood testing for heartworm disease and receive an appropriate preventative every month of the year.  For a more detailed description of heartworms, please visit the American Heartworm Society website, www.heartwormsociety.org.