We don't use anything. We do have mosquitos in the area, however our temperatures are too extreme for heartworm. In all the years my vet has been in practise, she has seen only 3 cases of heartworm -- all from dogs that had just recently traveled to Ontario.

Quote Originally Posted by ramanth
ProHeart 6 nearly killed her (it's now off the market).
They put it back on the market last year -- as far as I know it's still there, unfortunatly.