I have never used it on lice... Fleas and ticks, yes. With the fleas you can see some abandon ship straight away, others hang around, and die within the next day or so.
Don't be tempted to re-spray your pup, as you CAN overdose a dog with Frontline, and it can cause awful problems, can even kill.
Did you/Vet really work the Frontline into your pup's coat? It's a poodle right, curly coated? The spray needs to get thru to the skin.

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Emily
My opinion is my own, and I have the right to express it.