The cans I bought are really small so I fed him the whole thing. It didn't upset his tummy or anything and he sure doesn't have a weight problem (only 4 pounds)
I did feed him slowly though. I fed him with a spoon a few bites at a time. I bet it took me 20 minutes to feed it all to him. I'd say they would store easily if you put it in an airtight container in the fridge.