So about 2 weeks ago I went to Petco to get some mealworms for my gecko. I looked at the bettas and saw a male King Betta floating on it's side and it's swollen near the tail. I took him to the front and brought it to the employee's attention. Well tonight I went to get some more mealworms and there he was, still swollen and still on his side. They gave him to me for free and I brought him home. Put him in a 1.5 gallon aquarium with a filter and heater. I used spring water and some water I already had conditioned (I have a 55 gallon tank which I use to rescue goldfish). I put in some Stress Coat and a bit of AQ Salt. He is not swollen anywhere else except the area in front of his tail and he floats on his side. He has gotten more active and is trying to right himself, but that bloated part in front of his tail is like a bobber. I have not tried to feed him, because I know that is bad for a bloated fish. The tank is @ 78-80 degrees. Suggestions? He doesn't have Dropsy either, his scales are flat and he looks normal other than the bloating in front of the tail.
EDIT - I named him Leonidas since he is a King Betta and he's a fighter. :)