Another trip to the vet

This evening I spoke with the adoption (rescue agency) that we adopted Dylan from. I turned to them as I just didn't know which way to turn. I am broken hearted and very concerned about his little guy. We have had him 2 weeks tomorrow. When we adopted him, they said he is highly stressed but with time, trust and a little TLC, he will do fine. They also said he had kennel cough (which they said was normal) and sent him with doxicilline. He wasn't a spunky little guy ~ as they said he was rescued from SEACCA in Downey. He was in there much longer than normal but they thought he was so cute and so they kept him hoping he would be rescued. Which he was. After a few days, he would react to the normal situations most dogs would...... pig ears (which they love to chew on, bones, treats... food or water. We took him to our vet. He said may have a bad case of stress due to the conditions of being i the shelter for a long time plus he had kennel cough. Since he was already on doxicilline, they also gave him cough medication and 3 liquids (thru IV). Said we need to get him to eat, pretty much let him eat what he wants as long as he eats and drinks. I think we went to Petco and Petsmart 5 times in the last 2 weeks buying dog food then taking it back (because he wouldn't eat it). Thank god they have a great satisfaction return policy!
Now a week later he is worse... we took him back to the vet the other night as he is always shaking and refuses to eat at all nor drink water. The vet thinks he ma have distemper. Since they cannot give their opinion he did say if he was working at the shelter and this dog came in, he would have put him down. He placed him on Bastral (another antibiotic) and more cough tablets. We have to give him 12 oz of liquid daily *which he said should be 1 oz every hour. We are to take him back tomorrow to a recheck and take it day by day to see if he gets better.
This evening I called the rescue agency where I adopted him from. I explained to them how heartbroken I am that I may lose this little guy and I just needed guidance on what I should do. They said they had 2 other dogs from the same time period that Dylan was there that came down with pneumonia. One puppy and one adult dog. They have been treating both of them and are recovering very well. We are taking them back in the morning to the adoption agency as we are meeting them at their vet. She felt that Dylan has pneumonia also and not distemper. He may just need to stay at the hospital for a little while so that they can help him to recover.
Although we have had him for 2 weeks, we have all become attached to him and want very much for him to recover and enjoy life. He is very spoiled living with us ~ he deserves a great life and we cant wait till we can start doing more things with him.