Frontline dosage. Dog Food Advisor › Forums › Off Topic Forum › Frontline dosage. Viewing 3 posts - 1 through 3 (of 3 total) Author Posts July 21, 2017 at 7:44 am #103158 Report Abuse Kathy BMember We have a 20 month old puppy that weighs 70 lbs. question is since she is still growing would it hurt to use the 89 lb and up frontline? July 21, 2017 at 8:15 am #103159 Report Abuse pitloveMember Hi Kathy- This is a question for your vet. All I can tell you is the weigh ranges are there for a reason. July 22, 2017 at 6:38 am #103191 Report Abuse InkedMarieMember Stay with the dosage for her weight. Author Posts Viewing 3 posts - 1 through 3 (of 3 total) You must be logged in to reply to this topic.