Hello and welcome to the RTA forums !

You don't say exactly where you are starting from or finishing your trip, both are big States. If you were going from LA to Tallahassee then you could make it in 4 days, just. Much further and you are going to need some extra time depending how much further. It's a marathon and not a sprint so look at dividing your travel days up evenly and stop at between 500 and 600 miles per day and make sure you get plenty of breaks for both you and the dog along the way.