For a healthy cat at the right weight simply adding a bit of pumpkin to one meal a day not more than a tablespoon a day can keep everything moving smoothly. 100 canned pumpkin is the best optionas long as its without additives fillers sugar or spices. Male cats seem to need it more often in their food to help keep them regular and avoid blockages.
The nutrients in a dry one have already been removed. If your finicky cat refuses pumpkin consult your veterinarian for alternatives. I give mine some about once a week. Canned pumpkin pie filling contains sugar which is not good for your cat.