My Gizmo went thru Pancreatitis over a year ago. It is miserable and makes you feel so helpless to watch. I wish I could have taken it for Giz. His doctor said it was probably from the abundance of people food that he ate. Heck I even gave him his own hamburger patties, even rice and gravy because he didn't want that awful dog food. I thought I was pampering him but I was hurting him. Since then he has only he has endured HGE a couple of months ago, and I have been up with him last night hoping he is not trying to go thru it again. I bet my neighbors think I am a crazy lady when I take him for walks and stop to examine his poo after he has done his business. I called yesterday every couple of hours to ask the kids how their lil brother was feeling...but I digress..
The important thing is catching these things in time and being very picky what goes in those little stummies. You sound like a very attentive mommy and have not made the mistakes I did. He is lucky to have you. I will pray for his complete recovery and give him puppy hugs from "The Gizzard".