I just did a bit of research. Pool-water ingredients can be toxic when ingested, can cause ear, eye, and nose infections, skin problems, nausia, rapid respiration, excess mucous material (coughed up), burning, possibly cancer....Chlorine is the worst but bromine isn't much better. Wow, I had no idea it was this bad. My dog certianly won't be swimming in any pools unless they are UV treated -- but those are so rare and expensive, what are the chances?