The problem starts when a misquito collects blood from an infected dog. Circulating in the blood are tiny immature worms called microfilaria. These microfilaria must be ingested by the misquito before they can progress in their development. Inside the misquito, the microfilaria undergo a series of three changes, or molts.

Within two to three weeks, the microfilaria are transformed into infective larvae, which gain entrance to the dog's body in association with the misquito's next blood meal. Continuing to molt, the larvae mature into adult worms in about 200 days and begin producing thousands of the tiny microfilaria.

Typically, the long adult worms collect in the right heart chambers and major pulmonary blood vessels while the microfilaria are carried freely through the arteries and veins of the circulatory system. Together the parasites increase the heart's workload and restrict blood flow to the lungs, kidneys, and liver. Continued untreated infection produces an increase strain on these internal organs, which eventually may result in the death of the dog.

Visible signs of heartworm disease may not appear until a year or more after infection. In fact, the disease may be well advanced before the dog shows any signs. Because the signs vary, the disease may be mistaken for another problem. Typically, however, dogs cough frequently. They tire quickly, show labored breathing, and appear unusually weak. Often, affected dogs eat more, but lose weight.

After bloodwork and sometimes chest radiographs to evaluate the severity of the disease, the first step in ridding your dog of the parasites is to administer an agent to kill the adult worm. Injections are given on two consecutive days to kill the adults.

While the compound kills adult heartworms, you must rest your dog for several weeks to allow it's body time to absorb the dead worms. If your dog overexerts to soon after treatment, it's lungs can become severely congested, a condition that could result in death.

After the adult worms have been eliminated, the next step is to kill the microfilara. Your dog will return in three weeks and will be given an oral medication. After 10 days, the dog will return to the hospital for a blood test and if the blood is negative for microfilariam the daily or monthly heartworm preventative may be started. When the dog is at home after treatment, watch for coughing, lethargy, vomiting, diarrhea, or lack of appetite. If you see any of these signs, contact us as soon as possible.