Our Hav pup is 10 weeks. At what age should I start flea/tick meds and heartworm preventative? Can anyone recommend an oral flea/tick preventative and heartworm preventative for a pup this young? We definitely have fleas/ticks/mosquitoes in our location. (I prefer separate meds, and nothing topical.) Not Bravecto as I’ve heard too many horror stories. We have used Heartguard+ and Simparica for past dogs of different breeds. It looks like Heartgard can be given this young but not Simparica.