Do food manufacturers change the "recipe"?

I have been feeding Maxcat weight loss formula canned food for a couple of months now. The most recent batch seemed much "wetter", softer and sloppier than previous. Do these manufacturers change the ingredients? Sam has a sensitive stomach, and is a pretty fussy eater, so I would hate to think that all the good work I do in keeping his diet constant is wasted because the same food isn't the same.

Sometimes the cans are softer and wetter as it was just made or is at the end of the batch.