
We live in a hard water area, and although it is bad for appliances (although my washing machine is still going strong after 18 years), hard water is actually very beneficial to our health. It is good for our hearts! So, with that in mind, it is probably good for our pets' hearts too. Water softeners are bad for health (contrary to what we are led to believe in adverts) because they contain too much sodium, therefore really bad for hearts.
I feed raw bones, so even more calcium! Good for bones and teeth though.