Does anyone know how to go into Rover to offer a discounted rate for a second dog in a family. I cannot figure it out. Also can you change the rates once the family has already booked with you but before the dogs come?

To offer an automatic discounted rate for additional dogs you will go to edit your profile->rates->click the small link that says "additional rates" under each service. If you are already booked but want to change the price, you can modify the booking in the upcoming inbox. At the bottom is a place to change the rate. If the booking has already started, or it won't let you modify(i don't do boarding but this is how it works for other services), call rover support and they will help you out to change the rate.

Oh and I find that it is easier to navigate on the website than in the app for the rate changes!