Pneumonia and lung scarring

 Lung scarring can diminish over time, but doesn't always resolve completely.  It's a wait and see thing.

Any time you get long-term inflammation you can get damaged tissue.  In honesty, one of the best things you can do is find a *good* holistic vet that can help you detox your dog.  I'm not saying to 'leave' your vet ... not at all.

But a good holistic vet (http://www.tcvm.com is the Chi Institute -- traditional Chinese veterinary medicine -- one of several qualifying agencies but a VERY good one and I've had good luck referring people thru that) to help you clear away lingering traces of damage such drugs can do to the liver and other organs can be super helpful.

They will give an entirely different type of exam ... acupuncture in particular is incredibly helpful to speed healing and help clear away the remant of such infection.  I have ashtma and often get bronchitis myself, and I can tell you the relief is enormous.  There are also good supplements that can help support the respiratory system to maximize healing and help get this dog back on the right track.  Good luck.