There are two ways to cure with chemical treatments. The first is by smaller doses given over a longer period of time. This isn’t quite as dangerous as giving just one massive dose when a large amount of chemical is given. If the heartworms all die at once, the corpses travel through to the dog’s lungs. This would cause immediate death.
Treatment should never be given by anyone other than a highly qualified veterinarian.
There are also drugs available for heartworm prevention. These drugs kill them before they get to the adult stage. Dogs can still get infected during mosquito season but they don’t develop heartworms.
