I am new to this site, but like you have a constant urging to find out the real reason for my almost 13 yrs. old otherwise health dog and suddenly started being very fatigued and didn't want to eat or drink at all, upon awakening for only a week or so she would do this dry gag like little cough and then it would be gone... then her breathing became louder than normal and through the nose not with her mouth open... she was breathing really fast at times up to 60bpm and really labored and hard. I took her to the vet within that first week of noticing that it was not getting better at all, and they did xrays and labs, they then said it was a fully consolidated right lung and either was from a severe pneumonia or a tumor??? They gave a 100mg injection of Baytril antiobitiotics and more of it for 2 weeks through tablets.. the next day I returned to the vet as her breathing was still very abnormal and labored with heavy abdominal breathing, he then said it is appearing that it is more likely a turmor than a pneumonia but I was persistant to keep trying to feed her with syringes with RX food and water to give her the best chance to overcome this, I then asked if the vet could recommend a RX for something to lessen the resperations and labored breathing for comfort to give the antibiotics a chance to kick in.... he then gave her Torbutrol which did appear to lessen her fast heavy breathing, but even when she would go outside to pee, upon coming back inside she'd be labored breathing all abdominal really struggling and within the next 8-10 days I kept taking her back in and having the vet listen to her lungs as I did not want her to suffocate or be suffering... he then assured me that it was appearing that her symptoms were the same at the 2nd week mark and it was up to me to continue force feeding or put her to sleep-my choice he said... omg!!! as you can imagine I was devastated, but my husband started giving her servings of roasted chicken and for 2 days she ate it just fine and drank water on her own alittle…. so I was encouraged but to only be kicked back when suddenly she then went backwards again and would not eat again, so I again fed through the syringe with her routine meds. that was appearing that her abdomen was again severely caving in and out with noticeable fatigue and her rear legs seemed to be very unsteady within only 1 day.... so I took her back in as I could see she was having very labored abdominal breathing that was more intense and the vet listened to her and did not say much, so I asked is she suffering because she can't possibly be ok like this much longer? He then stated that I could take her home but he thought I should put her down for this is a very uncomfortable situration for my furbaby and that she was only acclimating to the condition she was dealt with and that it is not going to improve after the past 2 weeks of all this trying...I gathered my husband and 2 sons via telephone and they all came to me at the vets hospital and together we decided to put her to sleep for the most humane thing for her not to end up suffocating and suffering.... I have been so mad and full of guilt and grief as I really want to know what really was the reason for this lung to consolidate and help ease my pain of this heart break for my beloved and sweet Sadie girl..
There are a few fungal infections that can present like that and are often mistaken for pneumonia. What area do you live in? I live in the desert southwest (Arizona) and my dog was treated for six weeks for pneumonia before finally being diagnosed with Valley Fever (Coccidiomycosis). In the Midwest and eastern states, Blastomycosis can have similar symptoms and many vets are not that astute in testing for and diagnosing fungal infections.
I'm sorry for your loss.
Diana