I'm going away on saturday and coming home sunday evening. My dad never wants anything to do with the cats, and since I've not been free feeding them I'm wondering what to do.

Would it be bad to just feed them regular food for one day? I mean, Butter is on special food for preventing blockages (he's on medi-cal now...anyone know if that is good food? How do I know if it's high in sodium?) so anyway, would it harm him eatting regular stuff? Also, if I free feed them this once, will it mess up what I've been doing all along? I mean, it's just one day but....it's not like they're eatting much right now anyway