What worked for us was a product called the Enforcer, it’s got a red label and is available at either LOwes or Home Depot…can’t remember which one. A jug about the size of a gallon is around $10.00. We had a terrible infestation and I wound up using a combination of Borax (it dries them up) and the Enforcer stuff.
I also vacuumed the heck out of everything and threw away the vacuum bag immediately. We haven’t have fleas in 2 yrears. I did’t do anything for the animals so I can’t help you there.