You will need to rid the dogs environment of fleas. So you will need to flea bomb your house interior where they can hide. All the carpet window coverings , soft furniture like beds and couches and chairs and wash the dogs bedding. The dog must be bathed and your yard must be treated with spray chemicals. All this should be done on the same day or else you will simply be moving the fleas from one location only to return again soon. A flea preventive then should be applied to the pets. This is a process that may require repeat action until the weather reached freezing. The fleas don't live on the animals but simply jump on for a blood meal then jump off to hide in the rest of the places described above.
well, fleas are tiny guys, so i used to have front line plus but then i was reading online that fleas genetics are becoming immune to the formula and i stopped using that and then i read that olive oil works wonders, i gave him a good bath first, then I put a little bit of olive oil on my dogs neck and back, a little in his food , and it turns out he hasnt came home with any fleas since ive been using this method (I olive oil him onnce every two days)