I'm looking to get a Rottweiler or other large breed dog to train as a service dog for my mobility issues. Do you have any dogs like that currently?

You'll need to check with the office

Labs are the smartest big bread I have owened easy to trading but others can be two with little more work American bulldog and roughtwisers also can be good choice if raised right

You'll need to consult with the trainer to determine a best match. Usually if the training is complex you'll need a younger pup to work with and get used to the activities you'd like it to perform.

Sometimes they do.