Watch for red streaks on the surface on the body. These symptoms may include a white or gray film on the body. There are a number of effective treatments for many stains of bacterial infections. Three of the most common are tetracycline, penicillin and naladixic acid. Salt baths are another effective treatment.
Bacterial infections are often difficult to diagnose due to the many different types.
Orange or red streaks on the body is usually the only fool-proof method for the determination of a bacterial infection. Black spot is generally easy to cure. There are a number of commercially available treatments and preventatives. All fish are susceptible, especially the Silver Dollar and Piranha. It is fairly easy to diagnose and treat.