I used Revolution for about 8 months it made her real lethargic for a couple of hours everytime. It stopped working the last time and Summer was covered in fleas! When it was time to give her another dose I chose Bravecto, it is higher but it last 3 months and it didn't make her sick at all. So far its working great. Ihave not ddecided what we will do about the heart worm meds yet
