I thought I was going to lose my little baby last night

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About 2:00 am, Marcel started breathing funny - not like his occasional reverse sneezing that sometimes happens in the middle of the night, but something else. It was sort of similar in that it resulted in short breaths, but I couldn't get it to stop, and he was shaking and scared. Plus, it sounded different - more restrictive than reverse sneezing. At first, I wasn't terribly scared bc I thought it would resolve as his other episodes always have, but this was NOT going away - and I started to get scared. On top of this, my husband was OUT OF TOWN

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I got out of bed and turned the lights on, checked gums, they looked "okay". But, he didn't look right - he was sort of holding his mouth open a bit, his nose running a bit. Breathing worsened, I'm totally FREAKING now, his breaths are about 1/8th of a second long and I'm thinking these might be my last moments with Marcel, his body is stiffening. I try the Heimlich - nothing. Try it again. Nothing. Again. Nothing. He had so little air in him from his little breaths that there isn't much air to "push" out of him. He's still breathing his little breaths though and totally conscious. His little body was so tense and he was terrified.
I give Nutrical - he can swallow, so I give more. I set him down so I can get dressed and he runs around my feet hunched over - so somehow he's getting enough air to survive. I grab him and run toward our back bulletin board and CANNOT find the piece of paper w/ the ER vet. Have to grab yellow pages and page through.
Breathing worsening and again I think I may be losing him, he really is hardly breathing AT ALL at this point - I start crying and tell him to hold on. I don't know if his trachea is collapsing or what. I'm at a total loss now. I'm calling ERs and finally find one and it takes about 20+ minutes to get there - I'm driving 55-60 mph on regular streets, holding my baby. His breathing, of course, seems to calm a bit on the way. By the time we walk in, I
can't even hear the weird breathing. They take him after I fill out a form.
When they bring him out, he's PANTING at this point! And the tech says - "he's stable and can wait with you until the vet is ready to talk with you". So, the vet and me talk and we have NO idea what happened. Here's what we talked about
:
1) Collapsed trachea? She didn't think so bc he never tried to "cough" before before the episode or during. Does it sound like CT? I just don't know??? It did sound like he had a closed or almost closed airway. Like he was sucking air through as hard as he could, and could barely get ANY.
2) An allergic reaction? Possibly, but not really. He had odd drainage coming out of his nose at the vet which we though was odd, so we were both wondering what that was about. The drainage could indicate some sort of allergic response that went haywire.
3) Foreign Object? Don't know. But where would it come from when he was sleeping at 2am? We talked about it being in the nose (w/ the drainage), but we think he would've pawed at it. It could've been in his throat (and honestly, it SOUNDED like an object to me), but I couldn't dislodge it - and he could swallow after Nutrical, so???
Whatever it was, I swear - I almost lost him he was getting so little oxygen. I'm just grateful for the little air he was able to get, because it saved his life. By the time I talked to the vet, he was all perky and kissy and fine. Still having some runny nose. Occasionally doing a "harder swallow", but breathing totally normal. The vet said to give Benadryl when I get home. She said I can follow up with chest xrays and other things if I want, but she's as stumped as me and she never actually saw his weird breathing.