I know that the vaccine for kennel cough is about as old as I am, and is not terribly effective anymore. I also know that kennel cough rarely causes any serious issues with dogs, and if you keep up with the anti-biotics, you'll likely have a dog with no lasting issues. Keep an eye on both dogs, make sure they're breathing and eating normally, and you should be just fine. It sounds bad, but very rarely is. Most dogs get over it quickly on their own, without any medication.
Our dog caught it from our old roommate's new dog she got, and was fine within about a week and a half, without medication. She did need to treat her dog though, which was a much much younger puppy, and a more sensitive system.