They are deer food here, but I have not noticed that they are getting bushier as a result.

From what I know, you can cut out the older canes, to the ground, after flowering, as they do seem to flower better on canes/stems that aren't too old. Any shaping you feel is needed should be done after flowering as well.

I wish some deer would selectively prune my double back. The bloom quantity is unsurpassed in my garden right now but it runs all over the place. I like its natural shape so I haven't done much besides go after the occasional wonky stem and fight back against those darn runners. Last year, we did prune out a bunch of brown canes that showed no signs of life.

Good luck with yours!