Once bitten, it takes
6 to 7 months for the infected larvae to reach full maturity and begin reproducing in the canine’s heart, lungs, muscles and blood vessels. Adult heartworms could live and reproduce for as long as 5 to 7 years! To the naked eye, these worms appear to be almost like strands of hair as they are thin, near white in color, and can grow up to 12 inches in length. Once contracted, heartworm treatment is both painful for your dog and expensive for you. If left untreated, it can be fatal.