I discovered a flea on Keeran this week and had my SO pick up a flea treatment for him. We used Hartz on Monday but I'm still finding flea poo and just saw one running around on his stomache a minute ago while I was brushing Keeran. This is really frustrating me especially since his coat is quite long so there are more places for the fleas to run and hide! I want to go pick up Frontline or Advantage but since I used that monthly treatment from Hartz just this week, do you think it'd hurt Keeran if I put Frontline on him also? Also, how long does it take these things to be effective anyway? So far, it's been five days with very little, if any, progress.
Any help would be appreciated!