Heartworm disease is now more difficult to detect due to the widespread use of the monthly preventative. The old direct side test is no longer accurate and has been replaced by a more sophisticated antigen-antibody blood test. The safety and efficacy as well as the convenience of the monthly broad spectrum heartworm medication is well worth the added expense for the blood test.
The mosquito is the carrier of this parasite. Once a blood meal is taken from an infected (stray?) dog by the mosquito a two week molting process begins. At this point the mosquito bites your dog and injects the infective larva. The final destination of the adult worm is inside the heart and lungs.
The effects of the heartworm are to physically block the normal blood flow through your heart and to damage the lining of the heart muscle inside the right chamber. Although the process may take awhile the end result is to cause heart failure. You might notice a loss of stamina and a deep chested cough.
Recently a new medication has been approved by the FDA to treat heartworm disease that is much safer and more effective than the old arsenic treatment. The best form of treatment, however, will always be prevention. It is now time for all dogs to be tested.