How is heartworm transmitted?
Adult worms produce offspring called microfilariae, which circulate in the bloodstream and are ingested by mosquitoes when they feed from an infected animal. The microfilariae undergo development in the mosquito and are then transmitted to another dog or animal when that mosquito bites. Dogs are considered the most common host for heartworm, however heartworm may also infect more than thirty animal species (including coyotes, foxes, wolves, domestic cats, ferrets) and even humans.