This has been all over the news in the US for a couple of days now.
And from what I've heard, you'd have to drink an Olympic sized swimming pool's worth of water to have an adverse effect on you. That's for a human of course. A dog would need a little less.
However, still a dog or cat would have to drink a lot. What's been found is equivelent to an eye dropper full of the medications in that Olympic sized pool of water.
So IMO, it's good it made the news, but nothing to panic about yet.
CTV.ca | Pharmaceuticals found in four cities' tap water
Peggy