At the recent NAVC conference in Orlando in January 2014, it became known that the American Heartworm Society (AHS) has issued new guidelines regarding the diagnosis, prevention and treatment of heartworm disease. One of the most important findings discussed was the acknowledgment of possible emerging resistance amongst certain populations of heartworms to the common monthly heartworm preventatives.
Due to this possibility, the AHS is now recommending and emphasizing the need for year-round heartworm prevention across the country. With regard to diagnosis of heartworms, the AHS also acknowledged that it is important for veterinarians to perform BOTH an occult antigen heartworm blood test, and a test for heartworm babies, known as a microfilaria test on all pets tested. This will allow for more accurate detection of all heartworm positive dogs.
In regards to treatment of heartworm positive dogs, the AHS recommends that dogs be started on monthly heartworm preventative two months prior to treatment of the adult heartworms, as well as now a full two months of the antibiotic Doxycycline before treatment is begun. Hopefully, with these newer guidelines, there will be increased accuracy in detecting heartworms, as well as even better treatment outcomes. By stressing year-round prevention, it is hoped that there will be less heartworm resistance encountered.