Breathing heavy, puffing out the beard and forced exhalation [ burping ] when taking place at the same time are symptoms of a respiratory infection. What is his size [ at least length ] Is he at least 16-17" long ? You wouldn't want a young dragon that possibly is sick to brumate. His lethargy may be due to being ill. And just FYI, a electrolyte bath will have no benefit whatsoever unless he's actually drinking and even then it's not necessary.