I have an indoor only cat and she only ever eats dried cat food, but since I drink water all day long, she insists on drinking out of my glass. This used to freak me out but she sleeps with me [almost face to face] and breaths on me so I figure if there are parasites I'm going to get them reguardless. Haven't had any signs of anything negative so if she wants to drink out of my glass I let her. If I see her drinking I change the water before I drink but otherwise I'm not going to sweat it. We pick up more yukkies by just changing the litter boxes, so enjoy!!!!!