hairless rat having swallow,breathing diff

Question
our 3 year old hairless rat became grey colored, seemed to be struggling to breath. retracting in ribs,was cold to touch.too weak to eat and drink by himself. seen by vet-xray shows no pneumonia-given Baytril. xray shows all vertebrate are white except for 3 in neck that were visible but had grayish color/shadow . vet unsure what it is. cage is filled with papertowel litter, sleeps in a cardboard cracker box. wonder about an obstruction in upper airway? he doesn't try to vomit, he still struggles to breath, would  tumor show on xray? what else could be causing him  this trouble? thank you for your prompt response.

Answer
A tumor should show, but sometimes it wont. It also came on suddenly, which is not really something a tumor would do.

Rats cannot vomit, by the way, so when they do have an airway obstruction, it is a serious problem. The reason a rat cannot vomit is due to a strong barrier that is located between the stomach and the esophagus. There is no strength in the esophageal muscle that is needed to to force open the esophageal barrier and because of this, the rat is unable to vomit.

Sometimes if a rat is choking but is still getting oxygen, they eventually work it out on their own and you should leave them alone. When they cannot get oxygen is when the vet will need to put the rat under anesthesia and try to remove the foreign object causing the obstruction. This would also be visible on x rays as well.

It also depends on how trained the Vets eye is when they are viewing the xray films. Sometimes Vets miss something important and are quick to assume that things are one way when they really are another.

Has your rat ever been sick with a respiratory infection before and if so, how was he treated, what meds were used and for how long?

How long has this been going on?  
Are his extremeties blue or purple (check bottom of feet)

Is he relaxing and sleeping at all or restless, or hunched in a corner?