I have a Golden Retriever that was itching all over, I checked for fleas didn't see one. Vet found some droppings around her tail said to give her a flea bath and an antihistamine for her flea allergy.
That worked for a day or so----then found some research on Oil Soap for fleas---same one for furniture--and a lot of successful reviews--so I bought some and diluted 1/4 cup with 3 cups warm water--rubbed it in real good all over--rinsed her off-her coat was soft smelled clean-
she itched for an hour or so------then no scratching at all, and her belly had been red-now just pink--it worked. She's sleeping better and all night. What a cheap fix---then read cedarwood oil with a carrier oil kills fleas-----use that as a spray and this is 2 weeks now---no problems. I see a lot of Vets recommend the Oil Soap, wonder why my Vet never heard of it. It doesn't say anything on the bottle, just for furniture. So check it out on the internet. Molly had a great flea free thanksgiving and no more antihistamines-Bonnie