15 y/o pit lab is coughing/collapsing - X-ray result help

DEAR VETS… PLEASE HELP 😢 My boy, my baby, my Duke has been having some trouble with hacking and passing out - it’s happened three times in the past week. We are worried sick. BACKGROUND: Duke is 15 years old as of April 12, 2023. He is a pit/lab mix. He is the best boy, on no medications, fluctuates between a healthy 45-50lbs (curr 47.5) for the last 12 years, still playful and normal appetite and BMs. He’s had horrible teeth and had heartworm because of a prior owner’s neglect at 3 years old, when we got him we treated him for this and he was given injections and cleared of heartworm and been on preventative monthly with regular screenings annually ever since. His teeth haven’t ever caused an issue enough to need extraction but we brush them every few days. He’s also gotten fatty tissue masses around his body but none have been a concern checked regularly, and they have yet to affect his mobility. We take him to the vet every six months in his older years. Last year we had brought him in as sometimes excitement or heat made him breathe more labored than before, he was diagnosed with onset of Laryngeal paralysis which is common in labs and with his age, surgery didn’t seem the right fit especially with surgery resulting in extreme risk of choking since the flaps would be tied back. Instead our vet recommended changing his lifestyle a bit… For the past year we have lessened his physical activity (he still goes up and down stairs to go outside and get to our bedroom, gets on the bed/couch with an ottoman’s step help and light play indoors) to reduce breathing stress and try to keep his excitement down and cool as best as possible (summers in MD can be tricky). We also got a senior blood panel and x-rays done and nothing alarming came of it. She was actually pleased at how healthy he was for his age, minus his slight breathing issue. He’s been doing great with zero concerns and is only labored in breathing maybe 10 minutes total a day (getting home, and breakfast and dinner time are hard to keep excitement down but his breathing doesn’t remain labored)… there was, about 2 months ago, an isolated incident - Duke had thrown up violently after a few coughs. I’m talking projectile everything in his stomach. It was maybe 20-30 minutes after dinner and potty break, with no precursor to the incident. The vomit was brown and smelt like actual poop, not exaggerating. He threw up so hard that immediately after he collapsed and shook for a few seconds, but woke up and was absolutely fine and my vet advised to monitor and come back if it happened again. There has been no issues until 3 days ago. THE SITUATION NOW: Saturday - We’d let our three dogs outside to potty (we always go out with them even though the yard is fenced), and when Duke did his business he took a few paces towards me, did a singular old man “hack”, stumbled away from me and collapsed/fainted. I immediately went to his side where he was already awake (maybe 3 seconds went by), but it took him a minute or two to get his bearings enough to get up. We kept him resting but about an hour later, he got up from his dog bed and did a singular “hack” again and collapsed again. We were one more incident from driving the hour to the ER. Luckily he was fine, I made an appointment at the vet but emailed her the situation in hopes of being seen sooner. Thankfully they worked us in yesterday. His breathing she said sounds the same, but she noticed an irregular heartbeat not present on his last exam. We did an x-ray, which I’ll post here. We are awaiting blood panel results back - the same senior panel done before. They should be back today or tomorrow. She’d also asked another vet to listen/look at the X-rays and neither felt comfortable making a determination so they’ve been sent to a board certified radiologist. We should have those results in a week. She said his lungs seem “messy” and abnormal, and there is a dark pocket of air hanging out in his chest cavity, and the biggest concern she had was his heart seeming enlarged on the one side (right). She thinks the three white nodules are his arteries as they’re not present in multiple views. She sent us home with 200mg of gabapentin every 12 hours and he’s had 2 doses so far, but until there’s a diagnosis she didn’t want to do anything else. He’s been resting but still himself on the doseage which I’m thankful for. However he JUST was sitting in a chair outside in the shade (cool 65 out right now), woke from a nap with a few “hack” type choking sounds (2-3), I massaged his throat and chest area but he was shakey for about 5 seconds with no loss of consciousness and he kept his sweet eyes locked on me. I’m awaiting a call back from the vet, but I’m hoping for more input while I wait… MY ASK: Given the X-rays and his symptoms.. has anyone seen this before? If so what’s the condition(s) possible, treatment options I should discuss, and prognosis? To note… Money isn’t a concern, I just want to know what your opinion(s) are of our boy… he is literally like our child (all three of them are) and there’s nothing we won’t do to keep him comfortable. I’m praying we still have some years left with him. I appreciate all you guys do, and am very much looking forward to input while we await the vet/radiologist results. TIA 🥺❤️

Hello - these are great radiographs, and sometimes I'm truely sorry to have to follow professional guidelines when I'd like a good old speculate.  These radiographs have been taken by the vet who is managing this case, has examined the patient, taken as full a history as they can, has developed the pictures and directly or indirectly handed them to you - so why the delay in discussing the results?  Im sure that by this time they must have spoken to you about what they think is going on, or will have an appointmemt very soon to do so, with or without a second opinion being involved.  Given this, I have to be honest about the value that I - as a vet who hasnt examined the dog and isnt a specialist - can add.  At best, I can confirm what your vet (plus or minus radiography guru)  can tell you; at worst we will disagree or choose different wording, muddying the waters of your trust in your vet, who still has more information than me at this point.  For this reason, we are not an online second opinion service.  Regrettably.  However thankyou for sharing this interesting case and I would be fascinated to know what happens next.

Hello Liz, thanks for replying. So she and another other vets at the practice had actually said that because of the “messy” abnormal look of his lungs and the right side of his heart being enlarged, she referred this to a board-certified radiologist whom will interpret the results in the images which can take a week or two. I trust her with all three of my dogs and for several years she has been incredible, but she did not feel comfortable making a diagnosis without an expert opinion. We are also awaiting his blood work results. She was able to pretty confidently say she does not believe it is cancer, which is relieving. The waiting is killing us though… He’s had another hacking moment since the vet yesterday, and we are so worried about him especially because we live almost an hour away from an emergency vet. The 200mg gabapentin has been keeping him more sleepy and relaxed which I can imagine for what is going on is helpful. It seems that based on his symptoms and X-rays after some countless hours online, I wouldn’t be surprised if it was cardiomyopathy. But I’ve also read how serious this can be, and while I am not a vet whatsoever I guess I was just looking for other resources or reassurance while we wait. He is my baby, we love him more than can be put into words. 😢

Hello  Thankyou for that context: I can see that it is already clearly understood that your dogs' own vet / a specialist needs to make the diagnosis.  I cannot see a clear diaphragmatic line in these radiographs so a diaphragmatic hernia might also be on my possibilities list (they vary a lot in appearance); I also wondered about a tumour or heart disease.  These are all serious conditions but even if one of them turns out to be true, it's always better to know what you're dealing with and thereby what the options are moving forward.  I'm pleased to hear that a radiologist is going to be involved in order that the best choices are made for your dog.  I feel your angst with the stressful wait ahead - sometimes there is a fast-forward system for the radiographs of animals with breathing problems, but radiologists are very much in demand!  Hopefully you know from your vet at what point they need to see you back and I would be fascinated to know what is found in the end.