QUESTION: An aquarist has a cichlid with a white spot/wound about mid body maybe 3/16 inch below the dorsal, within a week the white increased to about a 3/8 strip from dorsal to belly. There was a thin white cottony growth (fungus?) but it appeared to be eating away the cichlids skin, and it appeared the outside skin was eaten away and was down to the ‘meat’. Despite its blackish color this patch was definitely fleshier in color. The fish died within a few hours. A local fish store informed the aquarist that yes a problem had arisen in the tank it came from. He gave him 200 mg Erythromycin said apply as directed (5 tabs per 24 hours 4 four treatments, w/ one water change) and that should solve any future problems. That did not work. When he came home to apply the first round another cichlid had what appeared to be a small white spot between his upper lips and eye. About 5 days later - he pulled out the cichlid (after sterilizing the other tank) and not only has it spread towards the other eye but there is a white film growing above its eyes.
ANSWER: Erythromycin should not have been used. The disease the aquarist seems to be dealing with is Flexibacter (Flavobacterium columnare), which is gram negative, while Erythromycin treats gram positive bacterial infections. I would have started with a blend of Furacyn and Kanamycin (Chloramphenicol is a better choice than Kanamycin if it can be found, but it is not easily found due to problems in humans). Pimafix shows allot of promise as a natural treatment for flex bacteria. Pimafix is effective for a broad range of bacterial and fungal diseases that typically afflict fish and other aquatic animals. Fish diseases that may be treated in accordance with this product include bacterial fish diseases, such as fin and tail rot, mouth fungus (often caused by the bacterium Flavobacterium columnaris); fungal fish diseases (such as those caused by microorganisms of the genera Saprolegnia and Achyle) and the like. Many fish diseases, it should be noted, are caused by different bacterial or fungal pathogens that often exhibit similar symptoms, so identification of a specific bacterial or fungal pathogen is not usually possible from mere visual inspection of the symptoms on the fish. Since the Pimenta extract (Pimafix) treatment of this product appears to have broad-spectrum effectiveness against many diseases affecting fish and other aquatic animals, precise identification of specific bacterial or fungal pathogens causing the disease is not usually necessary.
Additional salt is helpful too. A dip in mebromin or methylene blue (not to be confused with malachite green) has also helped speed cure for my fish. I have other treatments I have used, especially to prevent reoccurrence once the fish are OK (such as ”Medicated Wonder Shells”, which contain acriflavin, which is active against flex bacteria).
By Carl Strohmeyer