give them a few days ... and prune off the broken parts.. which will become apparent as they dry out ... or go off color ...

its nearing time that big mature plants might need pruning .. or cutting back ... consider that the dog just started the process early ... link below gives info on how to prune such ....

presuming he did not uproot the plants.. i dont see any reason they should die .... sounds not much different than if you had had an hail storm ...

ken

https://duckduckgo.com/?q=supertunia+pruning&t=ffcm&ia=web

thanks a bunch

Those petunia stems break so easy. I just broke a couple stems while weeding, and some aren't looking well because they were first blanketed with cottonwood cotton, and then immediately after, drenched with several days of rain and cloudy skies. It might not help a lot, but deadheading your macerated plant will channel more energy into producing new growth, which is what it desperately needs. And ditto everything Ken said.