Maxx prefers to drink out of the toilet and has since she was big enough to reach. We always make sure the lid is up, the toilet is clean, and we always flush a few times after cleaning the toilet.

Here in Canada, there are regulations that the water in the toilet must be potable (drinkable) in case of emergency (earthquake, etc) so as long as you don't use a toilet cleaner in the tank, your furbaby should be fine drinking it.