The discussion with your veterinarian about heartworm treatment should begin as soon as a positive heartworm test has occured. There are several different types of heartworm tests and all (when positive) are evaluating for an infection of adult heartworms.
When deciding on a treatment protocol there are several things to be decided upon. First, it must be decided how severe the grade of the disease is in you pet. Heartworm Disease is classified in grades 1 through 4. With the early grades there may be no clinic signs a treatment will generally be much more tolerated with these pets. To grade the patient there needs to be evaluation of the heart by two different views (a lateral (from the side) and VD (like the patient is standing up facing you) using radiographs (x-rays). With early heartworm disease there will be little to no change in the heart where as in later grades there will be extreme changes to the heart (especially the right side of the heart) and pulmonary vessels of the lungs. In some cases a CBC will be needed to evaluate between grades.
The difference in a Grade 1 and a Grade 3
Today’s treatment of canine heartworms involves the usage of an injectable drug called immiticide that targets the adult heartworms with the dosage dependant on the weight of the patient. Treatment protocol is aso dependent on the grade of disease decided upon with the use of radiographs and/or CBC results. At CCAH, we follow the American Heartworm Society guidelines for heartworm treatment, which is the safest and most effective way to treat Canine Heartworm disease.
Prognosis and Treatment
Grade 1 – Asymptomatic to mild disease, good prognosis, two treatments 24 hours apart
Grade 2 – Few to moderate signs and typical lesions, good to fair prognosis, two treatments 24 hours apart
Grade 3 – Severe signs and typical lesions, fair to guarded prognosis (may need symptomatic treatments and hospitalization, treatment consists of one treatmant followed by a second and third 30 days later 24 hours apart
Grade 4 – Very severe signs and generally has ascities (abdominal swelling), guarded to poor prognosis, treatment is generally not recommended but should be decided on case to case with your veterinarian.
All heartworm treatment cases should be placed on YEAR-ROUND(*) heartworm preventatives and retested 4 months after treatment to be certain treatment was successful.
* – Year-round heartworm prevention is needed lessen the chances for infection of heartworm disease in early and late months that heartworms are infectious via mosquitos and for the prevention/treament of intestinal parasites that are contagious to people, such as hookworms and roundworms (for more information about these parasites return to the main parasites page)