Heavy breathing of dog during relaxation

Dr Brown, my 12 year old Shep/Rotti mix has been panting and breathing heavy when laying on the couch with me or when we are in bed. He wakes up at night and gets very restless and starts open mouth breathing like he just got done running a race. The whole bed shakes-he is 100lbs. This has been happening for about 4 months straight. He is afraid of thunderstorms and has breathed like that during them since a baby but this is happening at any time and every night.

 

Answer from Dr. Gaylord Brown:
From what you describe this is a form of orthopnea, positional respiratory distress. This is most often caused by poor circulation from a heart problem. Your dog needs a work up that includes chest radiographs and possibly an ultrasound of the heart. Medications can help to prolong our dog;s quality of life. A delay in treatment may lead to congestive heart failure.