The 4-1-1 on Heartworm Disease

July 14, 2010

The sad truth, according to the American Heartworm Society, is that only 55% of dogs in the U.S. are on heartworm prevention medication, which means 27 million dogs are at risk of acquiring the disease. Out of that 27 million, it is estimated that 80% - 90% will acquire the disease. If not treated in time, heartworm disease has a 100% fatality rate.

HOW CAN YOUR DOG BECOME INFECTED? When Adult Heartworms reproduce, millions of microfilaria (baby heartworms) result. Microfilaria circulate in the blood of the host (infected animal). A mosquito bites the host, thereby ingesting the microfilaria. The mosquito then feeds on your dog, transmitting the infectious microfilaria into your dog's blood stream. The microfilaria molt in your dog's tissues for 3 - 4 months. Once the Microfilaria become worms (reaching up to 14 inches in length), the worms migrate from the tissues to the heart and surrounding blood vessels, where they mature to adulthood and the cycle continues. Adult heartworms cause severe heart and lung damage in canines.

IS THERE A PREVENTATIVE AND HOW DOES IT WORK? Yes. There are monthly heartworm preventatives. And it is much easier and cheaper than treating the disease after your dog has developed adult heartworms. Heartworm preventative kills the molting microfilaria in your dog's tissues. The preventative must be given monthly, otherwise it may be rendered uneffective. It is important to note that the preventative does NOT kill adult or near-adult heartworms. It is also important to note that if your dog currently has heartworm disease, consult your veterinarian before giving the preventative. Giving a heartworm positive dog a preventative prior to completion of treatment for the disease can prove to be fatal for your dog. For this same reason, all dogs should be tested for heartworm disease prior to beginning treatment.

CAN HEARTWORM DISEASE BE TREATED? Maybe. It depends on the stage of the disease. Stages 1 & 2 carry the best prognosis for survival (95% or more). Stage 3 patients have a fatality rate of 5 -20%. Statistics for Stage 4 patients are contradicting. Treatment involves killing the heartworms, which unfortunately, can also kill your pet. Dead worms can clog small blood vessels, causing your dog's organs to fail. Since vessels constrict during excitement and exercise, it is imperative that your dog stay calm, and possibly confined, during the months of treatment. The treatment is extremely expensive.

Your pet's hair, even if a double-coat exists, will not protect your pet from the disease-carrying mosquitoes that pass along . Heartworm-positive pets have been found in all 50 U.S. States. If you value your pet's life, heartworm preventative is an absolute must. Your four-legged best friend will thank you.

* A special thanks to my brother for suggesting this topic.