Devo was examined by a third Vet in as many weeks on Tuesday. From the existing, collected records, Dr. Wilson found a few puzzling results, but was at a loss about his affliction. I left Devo with Dr. Wilson for a few hours. She drained 1500ml of fluid from his lower chest while he stood there and licked her hand! He is more comfortable now and was quite happy to come home.
One possibility has come up based on Dr. Wilson's experience in Fresno. Valley Fever! Rather than describe it, here is a very good link.
Valley fever fools many vets and doctors (humans and dogs can get it) into thinking they are looking at a patient with cancer or a heart/lung disorder. As you all know, Devo was in Phoenix (it's very common here) for 2 months and spent time traveling through other parts of the country where the fungus spore that causes valley fever thrives. None of that in the Northwest.
We'll know more next week after more tests. After researching everything I could find, I'm now convinced it's valley fever. It is treat-able and survive-able, especially in strong dogs like Devo.
Sorry to be so detailed, but you are all dog owners and lovers, so if you can learn anything from what I am experiencing, that is my ultimate hope. It could save you time, money and maybe even the life of your fur baby.