Heartworm disease is the most serious parasite problem we see in this part of the world. This is regrettable because it is easily prevented. The cycle starts when a mosquito draws blood from an infected dog where tiny, immature worms called microfilaria are circulating in the blood. These microfilaria undergo two molts within the salivary glands of the mosquito before becoming infective larvae which are then transmitted by the mosquito’s bite to your dog or cat. The infective larvae move to the heart where they grow into adult worms reaching 10-14 inches in length. The adults produce thousands of microfilaria which circulate through the blood vessels ready to start the cycle again. Together, the adults and microfilaria can cause a variety of problems of the heart, lungs, liver, and kidneys, which can easily result in death.

Although heartworm treatment involves the use of potent drugs and has the potential for complications, it is far more successful than most people think. The overwhelming majority of patients goes through treatment with few side effects and return to a normal, active, happy life.

Heartworm treatment involves two stages—treatment of the adult worms and treatment of the microfilaria.

TREATMENT (Dogs)……
Patients are admitted to the hospital for a complete physical examination, laboratory testing, ECG screening and chest X-rays to ensure that there are no contraindications to treatment. Treatment protocol may vary depending on the condition of the patient. Normal treatment protocol consists of an injection of melarsomine which is followed in 1 month with two more injections given at 24-hour intervals. While undergoing treatment, the patient is placed on antibiotics and sometimes aspirin or steroids to lessen potential side effects.

Possible side effects are fever, lethargy, coughing, pain, or swelling in the back muscles where the injections are given. These are usually not cause for alarm, but call the office if any side effects are noted.

Restricted exercise is crucial for the next 30 days as adult heartworms are dying and being disposed of by the body. Exercise increases heart rate and blood pressure and can pump worm fragments into the lungs triggering potentially fatal reactions. Patients are started on heartworm preventive to avoid repeat infection.

Thirty days after the final melarsomine treatment, the microfilaria are treated with ivermectin. Due to possible drug sensitivity this step is omitted with Collies or herding type breeds.

FOLLOW-UP…
Heartworm preventive should be continued year around and a follow-up heartworm test is done in four months.

TREATMENT (Cats)…
Unfortunately, there is no safe protocol for treating cats so the best approach is prevention. KEEP YOUR CAT INDOORS! You can avoid heartworms and many other problems. If you do not keep you can indoors use Revolution monthly year round to prevent heartworms and many other parasites.