Holistic Care : Heartworm in Dogs : Treatment

95% of dogs infected with heartworms are treated successfully, and fatalities are rare. There is some risk involved in treating dogs with heartworms, because the drug that is used contains arsenic. The amount of arsenic present is sufficient to kill heartworms without undue risk to the dog. However, dogs with poor liver or kidney function may have difficulty breaking down and eliminating the arsenic.

Treatment to kill adult worms: Two injections of a drug called Immiticide are given 24 hours apart. It kills the adult heartworms in the heart and adjacent vessels over a period of about 30 days. Complete rest is essential after treatment. Some adult worms die in a few days and start to decompose; the remainder will die within a month. As they break up, they are carried to the lungs, where they lodge in the small blood vessels and are eventually reabsorbed by the body. This is a dangerous period, and it is absolutely essential that the dog be kept quiet and not be allowed to exercise for 1 month following treatment. The first week after the injections is very critical because the worms are dying. A cough is noticeable for 7 to 8 weeks after treatment in many heavily infected dogs.

Treatment to kill microfilaria: If microfilaria were found to be present, approximately three weeks to one month following treatment to kill the adults, the dog is given a drug (Milbemycin Oxine) to kill microfilariae. Seven to ten days later, a test is performed to determine if microfilariae are present. If they have been all killed, the treatment is complete. If there are still some present in the blood, treatment for microfilariae is repeated. Heartworm prevention must then be started on a regular basis to prevent further infection.