The importance of keeping your pet on heartworm prevention cannot be stressed enough. Heartworms are transmitted by mosquitos year round! It is a myth that inside dogs do not need heartworm prevention. However, inside dogs are just as susceptible as outside dogs, as it only takes one bite for infection to occur! A prescription (current doctor/patient relationship) as well as a yearly heartworm test (small blood draw for in house testing) are required to purchase heartworm preventative.
More information on heartworms can be found at www.heartwormsociety.org