I really like how Dr. Peter Tobias explains heart worm and for those that live in my area, maybe this info will make you a little less nervous.
http://peterdobias.com/blogs/blog/11...bout-heartworm
Wherever you stand, I believe this is good info to have:
Unknown Facts about Dog Heartworms Natural Heartworm Prevention
I encourage everyone to read, research and ask questions and hopefully all of us will make the best decision possible for our own unique situations and for each and every one of our four footed friends.