SFailed186, baby water bottles are actually mentioned in the second article. It says that these plastics were banned from use in baby water bottles in Canada but not in the U.S. (that's the WebMD article).
The things is, there have been a lot of harmful things that were not outlawed until decades later (medications that caused birth defects is what comes to mind right away). Even cigarettes were not thought to lead to cancer at one point. Research and actually observing side-effects can take decades. The problem with these water bottles (either human or animal) is not so much that you can't disinfect them as well, which IS a problem, but that they disintegrate differently than glass does, and the chemicals that are in them to make the plastic stronger end up in the water supply.
Just what the chemicals will do and how soom they leave the body is up for debate right now. In my opininon, it's better to stick with things that don't carry the potential risk. If you disagree, you are certainly entitled to your opinion. I just wanted to post this for people who may not be aware of the potential problems (I certainly wasn't 100% aware), and after that, well, the choice is yours. I would also encourage you to do more research on your own, so this is not just coming from some person on the internet.
Sorry, SFailed186, this was not all directed at you. I just watned to address to some things that you brought up.