[theBCnut]

Purina has a lower calorie count, so you probably do need to reduce his food amount or as you as doing, reduce his calories. If the tightness in his belly is signs of pancreatitis, then reducing his fat is imperative, but he also needs to be fasted for a few days or he could have a very bad case of pancreatitis- read LIFE THREATENING-so I REALLY wish you would not put off having your vet look into this. It really is a serious sign of serious pain.