Switching Trifexis out for Comfortis would not do anything because the flea adulticide in Trifexis is spinosad (Comfortis). There are lots of reports about spinosad only lasting 3 weeks.
Sentinel is the same heartworm med (milbemycin), but a different flea med (lufeneron). Lufeneron does not kill adults, but makes them unable to reproduce. I like using Sentinel and then Frontline PRN.
__________________ Crystal  , Ellie May (RIP)  , Rylee Finnegan  , and Gracie Boo🐶 |