I never use the whole can when the cats are having bowel problems. Can you freeze it in little containers and take it out as needed, or would freezing break down something essential in it? Anyone know?
I don't see why not; it's already been processed. The loss of nutrients in freezing is an issue with raw vegetables and that's why they need to be blanched first.
Never tried to freeze canned pumpkin, but I have made home made pumpkin filling (from a pumpkin) and froze that. As long as it's cooked first, it usually holds out well.
I would freeze it in small amounts using an ice cube tray. Once it is frozen, remove the pumpkin cubes from the tray and put them in a plastic bag. I tried freezing them once and left them in the tray, and they got really dried out.