Oh my gosh, this poor little wee one
! Been thru so much already.
Btw, did he have the kennel cough/bordetella vacccine at the store -- bc that's why he now has pneumonia...it's due to catching KC from the vaccine itself. KC can easily progress to pneumonia in young puppies and can be life threatening...as you're seeing.
I hope for the best for this little one...please keep us posted on the progress!