A few weeks ago I noticed that my betta Malysh developed something like a tumor on her right side. She looked deformed but was active and had a good appetite. Unfortunately her tumor grew really fast and Malysh began to feel weaker and weaker every day. Today I noticed that her scales stick out and she is really swollen. She looks really bad. Now I am pretty sure she has dropsy. Malysh shares her tank with another betta Misa. Misa is fine right now. Can she catch dropsy from Malysh? Should I separate them or it's too late?