Ask your vet about giving Buddy bear Comfortis it's a chewable tablet, works for 30 days. It is FDA approved, prevents flea infestations for a month. Make sure it's the one that kills baby fleas, larva, eggs and adults. Tell your vet what you have given your baby, you don't want to over medicate your pup. Speak to your vet before giving him Benadry. What you want to do is rid the dog of fleas, once the fleas are gone the itching will stop. Before using a flea shampoo I would speak to your vet, not all flea shampoos are safe for dogs, if Comfortis is used there is no need for flea baths