When we lived in Georgia, our dogs were on year around oral flea, tick and Heartworm prevention, which were very costly and I worried about the long term health effects of systemic pesticides. Now live in new state and a new puppy. I was determined not to go the pesticide route. We live in a rural area where we have a lot of wildlife going through our property. We have been using your Flea and Tick Defense ever since we brought our puppy home from the breeder last April. We have gone through a spring, summer and fall with nary a tick or a flea.