I have a betta that's always been "sick". She was a rescue from Walmart and has always had a swim bladder issue and floats at the top. Otherwise she is healthy. 5.5 gallon heated, filtered, cycled tank. Water change 3 days ago. All seemed normal. Yesterday I fed her as normal and she was fine. I went out of town overnight and my husband told me this afternoon that she was laying on the bottom (which she never does since she always floats). Her Swim Bladder was normal sized (another weird thing for her) and that she was breathing heavily. I had him lower the water level add an air stone and add prime in case something was wrong. I just got home and she is pale, breathing heavy and her scales are standing out. What do I do? Does dropsy occur this quickly? What can I do for her? I've removed her to a small bowl so I could get a better look at her and have meds on hand to treat if necessary. Edit: There is NO swelling of her body.