"PIE" Pulmonary Infiltrates with Eosinophils:

Some people call it Eosinophilic Pneumonitis. It's a condition SIMILAR to some forms of 'asthma' except it doesn't really come with constriction of the airways - really the airways and lungs are just swarming with unwanted, over-abundant "eosinophils" which are a kind of inflammatory cell.

These dogs may be feverish, they will usually cough or try to clear their throats too much, and they sometimes breathe abnormally. Chest Xrays may show changes consistent with PIE/asthma and then the bloodwork USUALLY contains a high to very-high Eosinphil count.

I very much like to give these dogs three doses of Ivermectin. Usually Day One, Day Two or Three, and then wait 21 days and dose a Third time. That is absolutely harmless overkill but leaves practically no chance for 'worms' or other 'parasite' to be attracting the eosinophils to the lungs.

^Heartworm status needs to be known^.

Steroids, in particular Prednisone, is the treatment of choice if you can afford the time it takes to kick in. And almost-always, you can.

Protectants (antacids) for the stomach, and even antibiotics (due to the high steroid use and to rule out some sort of bacterial player in a lobar pneumonia or other infection we don't see) are all indicated.

Antihistamines may be of some value, even though eosinophils aren't really 'fired up' by histamine-mediated reactions.

Cough suppressants are of GREAT value because tracheal and bronchial irritation from chronic coughing is certainly irritating and makes the inflammation the pet is dealing with, WORSE. A narcotic/homatropine medicine could be used.

PIE (Eosinophilic Asthma) has characteristics of an auto-immune response and in some views, even a semi-neoplastic process. Since they can get better on the longterm --> cancer seems like the least-likely situation.

There are other diagnostics. And there are ways to spend $21,000 diagnosing this with a Franchise Veterinary Specialty Practice. That work up would begin with a culture of the ear canal and a referral to the Neurology Service to help keep that department open - and then down to the serious work at hand.