We have now identified two variants or haplotypes of the sodium channel gene in the mosquito anopheles gambiae. Does ivermectin treat heartworms in dogs?" "it does not." "i'll give you that much." "but it doesn't work." "why not?" "because, as i said, heartworms have an arsenal of drugs that fight and kill the worms." "so, if ivermectin doesn't work, what do we do?" "you can use an anthelminthic." "but you must understand, an anthelminthic is something that will take a lot of dog's time to get used to." "that's why we prefer an anthelminthic that's already been used." "there's no doubt you have an answer for everything." "yes." "good girl.