I use Heartguard Plus. I have seen what the heartworms does to a dog
and I would never take any chances. Whether there has been any reported cases or not.... My babies mean more to me than that... if there are mosquitoes, there is always the risk. It is $25.00 for a year supply with a $5.00 rebate. Not to mention it effective on other worms with the exception of tape worms.