Itching More Condition_symptoms I Just Saw Flea Bites On My Dogs So I Put Frontline On Base Of Their Necks 2 Min Ago. Now Itching Faces More?

I just saw flea bites on my dogs so I put Frontline on base of their necks 2 min ago. Now itching faces more? - itching more condition_symptoms

I know that slowly spreads, the first line of the application site for the rest of her body. Is it that fleas jump from the back, in her body as the first line is not there?