There are no herbal treatment options.
Medically there are two options:
Fast kill: Where the dog is treated with IV drugs to kill the worms immediately. It’s pretty intense and has a very high complication rate.
Slow kill: Where the infected dog is put on heartworm preventative and the worms die off slowly over time.
Both have risks. Find a local vet that has a lot of experience with heartworms and rely on his/her expertise.
Doc
Don't use herbs or combine herbs with medications or use them during lactation or pregnancy without talking with your healthcare provider.