Are the prices I see listed for Drop In care the price per visit, or the price per animal per visit?

I'd recommend you message a few sitters who you're interested in and ask them to confirm their price for 3 dogs with drop in visits 3 times daily, before deciding who you want to meet.

Under Each person's profile, Services there's a link to "See Additional Services & Rates", which may list "Additional Dog Rate". Rover sitters & walkers set their rates differently and there is some wide interpretation of what's included in services.