Oh No!

So as most of you know my little man has been unwell since he was 10 days old. He got his first cold or something and couldnt breathe and ended up on oxygen in hospital, well he hasn't got any better.
As my daughter had broncholitis and was admitted 5 times into hospital with it in her first 8 months and then was diagnosed with asthma at 9 months, we have a pretty good understanding about breathing issues and when to wait it out and when we need to panick. Due to this we were also expecting D to be unwell but not this early :(
Last week he was admitted for 2 days in hospital with broncholitis (the fun begins :(  ) So I quickly rushed around calling our amazing paediatrician asking him to see D. 12 weeks of being continuously unwell is just not doing it for me at all. Our doc is awesome... Though he is booked out til March he quickly squeezed him in, and man am I glad he did.
So we are in his office and he is going through the hospital files and listening to me babble about what has been happening for the last 3 months and he looks up at me with crazy eyes and says " You are in trouble!"  .... Well thats great, just what I wanted to hear :( He also said that D is going to be worse than Mikky... Oh great again *sigh*
So the diagnoses..................
Master D is allergic to something. And this allergy isn't your typical skin rash allergy :( What ever it is is affecting every layer of his body. It is affecting his skin, his lungs/breathing, and also his digestive system. The other thing this allergy is causing is mucous, lots and lots of it too. The nose and throat etc are producing tonnes of mucous to kind of protect itself for the allergin, but this causes another problem. D's lungs are now full of mucous which shows up on an xray and is now in a super high category to getting pneumonia. ( Double sigh) Now considering he is only on formula this makes finding out what it is either totally easy or extremely hard ( I vote for the later). The other thing is it is unlikely to be the formula as D has been unwell even while I was breast feeding, so it could be anything in the whole wide world :( This is where my detective skills step in just like I had to do with Mikkys food allergy lol.
D has been put on a prescription formula for a week to see if there is any change. He had been on it 4 days and nope no change yet BUT... Yesterday we went to a friends house and she had a cat! The was cat hair floating around as she was molting. Anyway.. not long after I noticed D's face had gone all red and his eyes were all red puffy and swollen..hhhmmmmmmm that got me worried but also thinking. We have a staffy who comes inside occasisionally. When we got home the flare up had gone down which was good, but then Troy was playing with our dog and then came up and touch D on the face. Well a while later D's face flared up so much worse than earlier on and the eyes all puffed up. It has been 12 hours and his face is still gross and wiping it clean has not worked :(  My poor little dude. If this is what he is allergic too does that mean I have to get rid of my dog????? It is still only a theory and not confirmed but..... is it a coinsidence or not??????????